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overheating B20

21K views 27 replies 11 participants last post by  timb0 
#1 ·
Hello all,
I own a really hot 1966 122s. but I want it to be cooler than it already is. Well, what I'm dealing with is I don't know if the radiator was replaced when the engine was swapped.Is there a separate part # for the b 18 & B 20 radiators? I am missing the shroud plastic and do not have an overflow set up for the coolant.The fan doesn't look too big to me. A guy I know suggested a P 1800 clutched fan assembly or maybe an Electric fan? I was thinking , parts availability might be an issue. I'd prefer performance over originality, as it is hot out here in southern California.I plan on flushing the radiator,and installing a new thermostat. The guy at the Napa store said they had different temp ranges on the thermostats. Which thermostat would you recommend? I also was considering an Oil cooler as well and checking timing.I read a post about using purified water and corrosion inhibitor/pump lube as it would dissipate heat better, than coolant? If there are updates I should know about please let me know. I am afraid of heat damage. I plan on it being a daily driver. the traffic out here is hard stop and go. I bought the car in Oakland and the guy I bought it off of was running 20w50 in it. and I noticed on the highway it got hot climbing hills and would cool of coming down the hills. I would use the gears to slow me down. It appeared to drop the temp according to the gage. It is also hard to restart after it warms up. Should I install a water and oil temp gauges in my car? Like to be able to monitor it. I also use the heater lever which helps. Thanks for your input. Looking forward to hearing from you.
 
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#2 ·
Re: overheating B20 (1966122s4door)

Look all over the car inside out including any boxes that came with the purchase for information about the car's history. Those Volvo Green Books are very valuable!

If the previous owner had the car for many years then he/she is a valuable source of information otherwise maybe not.

From your description it appears that your car is running the stock 122 radiator and fan. When the car is in good running condition this system should be adequate for cool running on the highway with no AC and no hotrod driving. Anything else may need some cooling help.

The '66 122 for the USA came with a coolant overflow system. Look at the radiator neck - is there an outside connection for a push-on small-diameter rubber hose? Look near the pax side of the radiator's edge - is there a triangular flange for mounting the overflow bottle?

The coolant temp gauge in the dash will make rapid large swings giving the appearance of an abnormallity but actually just responding to coolant temp changes at the sensor. To test the gauge look at the needle position BEFORE you start the cold (overnight) car. Now turn the ignition key to "ON". If the gauge is original 122 the needle will not move because it is controlled by ether expansion in a tube from the engine to the gauge connection behind the dash. Start the car and warm to operating temp with all accesories "OFF" and car facing the outside ambient air but parked. The gauge should rise slowly to either side of midway then hold steady with the engine running about 2,000rpm and the heater valve closed. Let the car idle for a while and notice that the gauge will show hotter and possibly edge toward the last green area then hold a steady temp. Now turn the car "OFF" and watch the gauge - the needle should go to max hot and may even start to disappear behind the dash. This is normal.

As to poor hot restart - you will want to chck the engine's ignition timing, valve lash settings, spark plug range and gap, distributor/points settings, carbs' setting, etc. before being able to make an assessment of overall condition.

Given that the car is not original it is possible that a B20 engine was installed using many B18 components - time will tell.

As to spare parts - NAPA is a good source for those little rubber caps that go on the tires' air valves.

To get an idea of the aftrermarket support for the Volvo Amazon click around on this...

http://www.ipdusa.com/Volvo-122/c-1-71/

There are many other parts suppliers on the www.

If you keep the car in a very mild climate year-round then 20W50 non-synthetic oil is OK. If the engine is healthy oil additives are a waste of money. Same for coolant and fuel.

A radiator flush should show the health of the coolant system - be sure to include the heatrer core and all hoses in the flush and don't use a flushing agent - just water. Yes, collect the flush and discard per local ordinances. Use 50/50 cheapo antifreeze/tap water in the cooling system. The thermostat's temp rating does not affect high operating temps but will affect gas mileage in very cold climates during initial warm-up. Source new radiator caps of the proper application and install an overflow system. This means that the cap on the radiator is not spring-loaded and looks just like a metal cap on a small jar. The new spring-loaded thermo-cap on the overflow jug will control any boil-over coolant escape.

Having extra gauges to monitor engine operation and health is always a good idea.

As to radiator and fan arrangements - do you plan to run AC?

If possible post some pics of the car and engine so we can see the carbs, manifolds, radiator, etc.

More later.

George Dill
 
#3 ·
Re: overheating B20 (gdill2)

The 67s had the overflow bottle. Most of the 66s just had an overflow tube down the side of the radiator.
You should check your ignition timing. Should be at least 15-20° before top dead center. If it is not, it WILL overheat! It will also be low on power and a great deal of heat will be transferred to the exhaust system. This can burn or melt your pipe and crack your exhaust manifold!
 
#4 ·
Re: overheating B20 (gdill2)

Too bad for Napa or noda?don't need caps
I thinking they upgraded the engine componets and carbs and head,but just kept stock equiptment ?like you said.I havn't pulled the cover off my valves yet.Walrus 3 informed me to look for umbrella valves .If I can see them on top it has a 18 heads If not it's a B 20. He gave me dimensons on the stems to measure as well.If it turns out to be a B 20 head I'll go with what lash vrs a B 18a? I am afraid to improperly set the lash.must first identify the head,correct? I must admit I do like to hot rod and I MUST have AC.but will baby it till it is healthy.that doesn't mean afterwards I will beat it like a red headed step child .
there is no nipple for connection or mounting bracket. There is however a metal tube on driver side of radiator which lays on top and along side radiator. Summers are really hot here in L.A. but I would guess the rest of the year would be considered mild?adatives being a waste of money is a Good money saver.Thanks.Hav not performed temp sensor check yet .don't have a tach?to tell if I'm at 2,000 rpm.I am plannig to get a Tach,water temp ,oil temp ,volt ,amp & vacuum gauges to monitor temps and sealing/valve ?cyl?condition?thanks 22ing a bit. Regarding radiator flush,don't use flushing agent because it will cloud results ?or because it is damaging to system , or both?Plese for give the question but ,are you recommending I flush the system my self vrs having a shop perform it?I only ask because if they have special equiptment ?I know Prestone use to carry a flushing kit to put inline with the coolant system,should i try to obtain one of them?and with the original oil cooler system ,I don't have the round unit. There is a block off plate where the water tube went to the filter cooler,there is a water drain on mid , left side of filter about 6" to the left?there is no lever on lower drain on block there is one on lower driver side of radiator. what should I not do?I don't want to create a problem ,or prolong one . After I get I.D. on parts I will plan to start making adjustments.At what stage can i check compression ,after valve adjustments ,right?



Modified by 1966122s4door at 9:21 PM 7-19-2009


Modified by 1966122s4door at 9:23 PM 7-19-2009
 
#5 ·
Re: overheating B20 (Walrus3)

thankyou heres a pic.if it is a B18 A converted to an B 20 ,will the timing be different?sorry I 'm trying to juggle new info of two or more engines,and figure out this posting process.Oh well trial by fire I guess thank you.Jason


Modified by 1966122s4door at 9:24 PM 7-19-2009
 
#6 ·
Re: overheating B20 (1966122s4door)

Your photo account is "...1965..." and your user name is "...1966..." - how many 122's do you have?

The upper radiator hose is kinked at the lower curve and is the wrong hose.

The radiator cap is not original and could be of the wrong application.

The radiator may have been repaired - looks like a hit opposite the fan. If so the total cooling capacity may be lower from the repair.

Before you flush the entire cooling system operate the heater control valve and blower to be sure hot water is passing through the valve. Leave this valve open during the flush. Have a catch pan under all drains then open/close each drain just a little to be sure it will close back without a leak. With the engine off remove the radiator cap and note the water level and any deposits. Open all drains. Empty catch pans as needed - long live the EPA! Using a garden hose running very slowly start filling the radiator while noting the color/composition of the fluid coming out of the drains. As the radiator fills start the car and run at idle with the heater blowing. Try not to let the radiator overflow. Once all drains run clear close them and fill the radiator to a just visible level. Replace the radiator cap and watch the temp gauge as the engine idles. If it stays in any green/white area all is well. Look under the dash around the heater control valve - any leaks? If not and no leaks under the hood shut off the engine and watch the temp gauge - it should move quickly to the "HOT" area.

The next step might be to source the correct radiator cap, thermostat/gasket and hoses/clamps before filling the coolant system with cheapo 50/50 antifreeze/water. These new parts will eliminate many of the usual areas causing cooling problems...

http://www.ipdusa.com/Volvo-12...1-113/

Another area of concern would be the fan belt being the wrong application and/or improperly tensioned. The water pump pulley must turn at all times under all rpm's and running conditions. Because you are new to the car and have great concern about its tendency to run hot consider installing a new thermostat/gasket and new water pump/gaskets along with the correct new upper/lower radiator hoses/clamps. A new (correct) fan belt is cheap insurance.

Does this car have a generator or alternator?

As a compromise set the engine ignition timing to 15D BTDC and the valves to 0.017" Go - 0.19" No-Go.

Does the distributor have a vacuum line attached?

If possible clean up the engine compartment using a spray-on bio cleaner and catch the rinse water.

Remove the distributor cap and take a close-up picture of the innards.

Same for the coil, fuse box contents and ignition switch on the dash.

We need to see which '65/'66 original components are on the car.

What led you to believe the car has/had a B20 engine?

More later.

George Dill
 
#7 ·
Re: overheating B20 (gdill2)

good eye ,the photo bucket account # was a typo in the dark I missed before I hit return. After I got that far I was afraid to mess with it . That is why It wrongly says 1965 instead of 1966. Sorry for the confusion.

The reason I Thought the engine was a B 20 is because the guy I bought the car off of told me it Was A B 20 and was not the original engine, but had work done to it by a previous owner.He said the manual was not for the B 20 ,but the B 18 , was close enough mostly to get an idea.On top of that well meaning ,nice guy I know ;who works on cars and owns a volvo wagon version of the saint car(p 1800?) looked at it after I first bought it and said it looked to be a B 20.He recomended finding this site .He said you guys would probaly know alot more about it.Because I didn't know what to look for,and knowing from dealing with bikes there is the right way ,the wrong way and in between?I guessed it was maybe punched out?So I ended up chaseing my tale
And being cautious with fear I realy didn't want to screw things up.I hope once it was identified I would have a safer chance of correctly working on my car. I guess i'm a bit nervous,but can be helped

yes It looks like the car has been hit in the front end ,there is bondo on the nose areas.and where the two grills go the surrounding metal is tweedked,also the front and rear bumpers look twisted slightly and low to one side in the front.I know the left rear was hit .the rear door is boogered and moulding partly missing. looking down from the 2nd floor @ the car you can see the driver side rear fender flare around the wheel well is not as proud as the right side.

I think I saw the proper cap on the sight you gave me?

the guy I bought the car off me said the fan was removed,but the heater still worked,just would take longer?will this hinder the flush technique?
thank you I will work on clean up an post pics of the distributor and I think it's a gen?I found a repair bill in the manual I got with the car.I thought it was weak out put in gen.check charging new bat ect.?I find it.
don't remember seing vac line on dist.i do recall a condensor though.I'm working on the pics.thank you george

 
#8 ·
Re: overheating B20 (Walrus3)

I have what you stated as to normal for 66.

which is better,a pressurized or sealed sys?I'm guessing the later because they switched to them.

Also, my goal right now is to iron out the hot running and get every thing up to specs,so to speak and then go from there .I'm going to set the timing,but I don't have a tach on my car or timing light/ gun.Guess I'm going to install one.Btw out of curiosity what is the red line ,or should be the red line?tachs usualy come with a rev limiting dial don't they?and they seem resonabl price wise. but at what point,would you go for future upgrades ,since your at it?future goals are AC,more effective charging system,body work(wich I can tackle as I'm useing the car)later interior,last but not least performance / handleing ect. I'm thinking first get car in tune then see.Sorry I get excited and have been known to get the cart before the horse.thanks again.
 
#9 ·
Re: overheating B20 (1966122s4door)

Quote, originally posted by 1966122s4door »
I have what you stated as to normal for 66.

which is better,a pressurized or sealed sys?I'm guessing the later because they switched to them.

Also, my goal right now is to iron out the hot running and get every thing up to specs,so to speak and then go from there .I'm going to set the timing,but I don't have a tach on my car or timing light/ gun.Guess I'm going to install one.Btw out of curiosity what is the red line ,or should be the red line?tachs usualy come with a rev...

Radiator cap - is the radiator the original 1966? Hard to tell. Once you get the '66 radiator cap you can install a temporary overflow bottle. Back in '69 on my '62 122S 4-door I used a piece of old rubber fuel line and a dish detergent plastic bottle but it may be best to buy a cheapo generic kit at the local auto parts place. When the coolant pressure overcomes the spring tension on the cap on the radiator liquid will flow into the overlow jug UNLESS the cooling system has leaks in which case the pressurized coolant will escape out the leak(s). IF the new radiator cap has a two-way flow feature the coolant in the overflow jug will be sucked back into the radiator as the temperature/pressure lowers. If the cap is just one-way (out into the jug) then the system is just catching any coolant overflow and not functioning as a recovery system. BTW, if your cooling system is healthy the overflow system won't make the engine run cooler.

If you plan to adjust the engine ignition timing yourself (and set the valve lash) you WILL need a timing light and a hand-held tach/dwell meter. The cheapest timing lights are powered by the spark plug wire and are not worth your time. Best for your needs may be a timing light powered from the battery and having a pickup that clamps on the #1 plug wire.

Us old guys can time a B18/20 without a timing light just as we can set the valves with a modified knife blade and the points by sight after which we set the carbs by ear then drive another 50,000 miles and do it again.

This could happen to you given your enthusiasm but first you should enjoy stumbling through everything and posting up here on SS so we can enjoy the ride with you.

PS: the redline is just before the engine explodes.

George Dill
 
#12 ·
Re: overheating B20 (Amazon63)

Quote, originally posted by Amazon63 »
In the picture above, what is that thing left of the ignition switch? (in the spot where the ignition switch usually is placed)

Is this some sort of lamp?

That's the old ignition switch. The new ignition switch is where the Cigarette lighter used to be.
 
#13 ·
ok so I'm resurrecting this thread because I have an overheating issue. my 122 is a b18, and since picking it up its taken a long time to get any heat in the engine. as I suspected, there was no thermostat. I put in an 82°c thremostat, and now it warms up quickly but then it runs at the top of the range of the in dash temp gauge.
I've heard stories of rubber and other junk crudding up the head and causing low flow, and I'm hoping that I don't have to have the radiator re cored. tomorrow I'm going to try running a coat hanger into the head and see if I can find anything.
I've tried a bottle of radiator flush / cleaner.
anything else I should try / chuck out before I take it to the radiator shop?
 
#14 · (Edited)
If the engine did not overheat when there was no thermostat in place, it is unlikely that you have a blockage in the engine or the radiator. The first thing to confirm is that the temperature gauge is reading correctly. I have no direct familiarity with the 'odd' Amazon gauge arrangement so you are on your own with that. If the gauge is working correctly, check the thermostat. If the B18 is like the B20, there is a vertical by-pass pipe directly below the thermostat. You should be able to see the top of this pipe with the thermostat removed. When the thermostat is closed, coolant circulates down this pipe, through the pump and back into the block. When the thermostat is open, there should be a fitting on the bottom of the thermostat that should move down and seal off the top of this pipe. This forces all of the coolant through the top of the thermostat and in to the radiator. If you have a non OEM thermostat, it may lack this close off feature which is allowing some of the coolant to by-pass the radiator causing the engine to run slightly hotter than what the thermostat temperature is set at.

If the gauge checks out and the thermostat is correct, then you can start checking for blockages.
 
#15 ·
Yeah I'm wondering about the gauge. When it was running hot, there were a couple of times that it was getting really close to pinning the hot side of the gauge. I pulled over to let it cool down, but never smelled any coolant venting or heard any valves knocking. the odd thing was that after just a few minutes of cooling off, starting it up again immediately dropped the temp by half, which leads me to believe that there is some sort of flow problem. I wonder if the impeller on the water pump is worn. That would be worth the $40 on a new one to try out.

The thermostat that I put in is brand new OEM, with the flow restriction thing at the base. I popped that in some 100° C water this morning to see if it opened, and it does although it doesn't seem to open very wide.

I may pull the probe end of the gauge and attach a gauge with a readout of temp, put the thermostat back in and give it a go and see if the gauge itself is wacky (i hope not, those things aren't cheap)
 
#16 ·
It seems like you are on the correct path. Checking the gauge operation first is probably the easiest thing to do. I would assign a low probability to a worn impeller unless somebody was running tap water in the cooling system and there was a lot of corrosion, in which case you would have other issues.

Since the thermostat appears to be correct, try a quick test with opening and closing the valve to the interior heater with the interior fan running to see if it makes a difference to the steady reading of the gauge. If running the interior heater brings the gauge closer to its normal operating range, you may have a compromised radiator in which case its off to the radiator shop for a flush! However, before you do that, inspect the radiator to make sure that externally it is not plugged up with bug guts or bent fins! I have an NSX. When I bought it the operation of the air conditioning was marginal. Close inspection revealed that the two condensers were caked with grasshopper remains. The bottom of the condensers are probably about 5 - 6" off the ground and ideally located to collect bugs. Cleaning and carefully straightening the fins restored the operation of the air conditioning.
 
#17 ·
Yeah the first thing I did was to check the exterior condition of the radiator... This particular car came with "factory" air con, so the radiator sits partially behind the condenser and all of the fins appear to be unblocked and straight. I'll probably blow it out with a pressure washer for good measure anyhow. I tried running with the heater on and off, it didn't seem to make much of a difference. but at least the heater core isn't leaking.
 
#18 ·
OK so I flushed the system with some radiator flush stuff with the thermostat out. Then I pulled the radiator and back flushed it with the hose and there didnt seems to be any flow restrictions, but it does look like the radiator was repaired at some point. I also pulled out the non-functioning AC condenser, and put in a new water pump.



Everything went back together pretty smoothly, I started it up and the engine warmed quickly and then held a good (although warm-ish) temperature idling in the driveway. Nothing was leaking, so I went for a ride around the block and the engine got really hot again almost as soon as I was driving.

I have someone that can re-core the radiator, but aside from that I'm out of ideas.

I know that a vacuum leak can make a car run hot, but that would do the same thing with or without the thermostat, no?
 
#19 · (Edited)
not sure if you're running without a thermostat, but it needs to be in. when it opens it closes off a bypass to allow full circulation. Edit- I see now you have the correct stat.

Also, when I did mine I removed the draincock at the right rear of the block and blew compressed air into it, all kinds of crud was flushed out. also the long heater pipe that goes from the front to the back on the right side of the engine.

Do you have new hoses, including the heater?
 
#20 ·
So once the car is up to temp, the heater hoses all get hot but not the radiator or radiator hoses. The radiator didn't have any flow problems when I tested it, so it has to be something in the block. I'll probably end up replacing the radiator with an aluminum one eventually, but I need to sort this out first.

My next attempt to figure this out will be to pull all of the heater hoses, and either replace them or clean them out. Also blow compressed air through the engine block drain, and the bypass tube.
 
#28 · (Edited)
My 122s is doing the same thing. Runs cool without the thermostat, and goes to the red line on temp gauge with brand new thermostat. Once the bypass is covered by the thermostat, the flow stops, and it gets hot. Bottom radiator hose is cold and top hose just warm--not hot.
Have you figured out what caused your problem? I'd surely like to know what to do next.
 
#24 · (Edited)
If the flap on the thermostat is closing off the by-pass and the interior heater valve is shut off, water pretty much has to flow through the radiator and the radiator hoses should be warming up. Is it possible that at some point the little by-pass pipe got knocked down and the flap on the bottom of the thermostat is not closing off the by-pass pipe? If so, then the coolant can still be flowing through the by-pass pipe which is allowing some of the coolant to by-pass the radiator circuit. Some coolant will still flow through the radiator so it should get warm; but, the engine will run hotter than it should because some of the coolant is going through the by-pass pipe.
 
#25 ·
Yeah Guy I'm thinking that little pipe could be it too. I asked about them here a couple of years ago wondering if I needed one on a boat head conversion. Got some good anwsers and put one in. (motor's still sitting on a stand)

I might have started a thread about it that shouldn't be a hard search. I gott'a start my night shift or I'd look for it.
If I'm late I could get fired before I get layed of next week. LOL
 
#26 ·
Yeah Guy I'm thinking that little pipe could be it too. I asked about them here a couple of years ago wondering if I needed one on a boat head conversion. Got some good anwsers and put one in. (motor's still sitting on a stand)

I might have started a thread about it that shouldn't be a hard search. I gott'a start my night shift or I'd look for it.
If I'm late I could get fired before I get layed of next week. :)
 
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