How bad is my turbo?

Rmind · Dec 14, 2014

Spark plug 1

2

3

4

5

spinall4 · Dec 14, 2014

Rmind said:
I am slowly learning more about the rebuilt process and agree about the importance of rebalancing. What does CHRA stands for by the way? I understand it must be the two wheels assembly. A quick search found some shop that would balance only for about $55. I would prefer to find something local but that may be tough.

Also I was planning to possibly get an IPD or Cavali turbo next year. But I will have to have a tune then, so it may not happen very soon.
For now I need the turbo back in the car within 9 days and still have the slave cylinder, clutch and flywheel to replace.
I would be interested in porting but I need to learn more about it.
What about the cracks? Isn't it an issue that needs to be addressed? Is it worth rebuilding the turbo without fixing the cracks?

Ok CHRA is the center part with both the compressor wheel and exhaust wheels with both the compressor and exhaust housing off. Center Housing & Rotating Assembly. This is what the shop would break your turbo to if they were going to balance the turbo for you.

A CHRA looks like this:

If you were comparing it to a motor, the CHRA is like the internals of the motor that do the work. They are under a huge amount of stress being spun to 100,000 RPM plus and exposed to exhaust gas temperatures of up to 1600F (some times even higher).

If you need to put this back together in 9 days, you may not have time or want to put a new compressor wheel on.

If you keep the compressor wheel, at leas take a minute while you have it apart and sand down the damaged part with a dremel tool with the sanding drum to clean and smooth out the damaged area. Do this slowly as you don't want to get crazy, you just want that scoring cleaned up on that one blade. I have seen turbos work like this for a long, long time, but eventually at some point the compressor wheel may fail. If your putting on a new turbo 1 year down the road, not really a big deal.

What the damage to the compressor wheel will probably do is cost you some effiencey, which means the air made from the turbo will be even hotter. With an after market intercooler no big deal. With the factory garbage intercooler you will just heat soak it that much faster.

While the cracks in the exhaust housing can't be good for performance overall, I have yet to see a higher miles use K24 come off an R and not have those cracks in it. For sure if you are just going to replace the turbo in 1 year then I would put it back on the car and run it cracked. It will be very hard to find a used housing that hasn't cracked already.

Porting the turbo exhaust housing and manifold are something that are very easy that ANYONE can do at home as long as you have a decent air compressor (not one of the pancake 1 gallon/1hp units) and you can buy/find an air die grinder. You can find bits local at a lot of industrial supply places. You want 100% real carbide burs, that will cost about $20 bux each.

With a small compressor and taking time to let your compressor cool off while you inspect your work and do other things it will take about 1 full day of work to port the turbo and manifold.

If you take the turbo to some one to have it balanced/and or the CHRA rebuilt by them you can work on porting the turbo/manifold while the turbo CHRA is dropped off with them. If you are just going to upgrade the turbo in 1 years time, I don't know if its really worth it to port the turbo at this point.

Here are some photos of what porting on a 2g DSM exhaust manifold and turbo exhaust housing to give you an idea of what the process looks like.

The idea with porting is not to go cray, but simply to use the gaskets that we already have and lay them down on your parts then mark the areas of metal with a black sharpie marker. Then you have a "template" on what to port and open up. You are not going to make 1000 extra hp with this mod, but what you are going to do is make the flow of exhaust gas through the turbo much smoother.

contrast · Dec 14, 2014

Deposits from burned oil on all plugs. Definately lean mixture too.
3rd cylinder plug shows signs of coolant burn. Can be cracked cylinder. Having seen about 5 different Volvos with cracked cylinders and the cylinder that has failed always had a plug looking similar to this. Must pull head to make sure. Coolant test might help too.
When did you last replace plugs?

Rmind · Dec 14, 2014

Thanks spinal4 for the detail description. I understand better the turbo rebuilt process.
The real concerned now has shifted to the potential cracked cylinder 3.
I bought a compression test kit and the sales person there said that humidity in plug well is also an indication of coolant in the cylinder. I apparently do have that too:

Cylinder 2 has some too but less:

Cylinder 1, 4 and 5 seem to be fine.

I have a cheap boroscope and will look inside the cylinder next.
My understanding is that a crack cylinder wall means either a new engine or darton sleeves, as this is not fixable. Shims between cylinders can only prevent cracks but not "fix" a crack once it is there.
After the boroscope, I plan to do a compression test, and then take off the head. I guess I will not be driving the car in 9 days.

contrast · Dec 14, 2014

Compression test wont tell you anything imo. Baroscope might see the crack, but not 100%.
Removing head is best. Also cylinder leak down test (volvo has special tools/procedures for that)

spinall4 · Dec 14, 2014

FU!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

Cracked Volvo R blocks make me a sad panda.....

Sounds like you have an excuse now to build it. Go buy a $1000 beater car to drive and go crazy on the R. Built block with sleeves, better internals, ect. Take your time and build it right, don't rush through it and get finished only to find there are things you missed during the rebuild that you wish you had done.

Rmind · Dec 15, 2014

So I will skip the compression test. And take off the head. Most likely, it will confirm the diagnosis of a cracked cylinder. In this case I plan to go with darton sleeves. For this I will need to take the engine out to get the block to a machine shop.
Is it possible to remove an engine without the head? The attachment point for a lift are on the head isn't it?
I was in the process of removing the transmission. Could I lower the block without the head and transmission on the transmission jack or would I need to put back the head to lift the block?
At this point I may as well lift the engine first before I remove the transmission and the head.
I am still wondering what caused me to run lean? Can simply a new FMIC and downpipe cause this? Or is it because of the silent failure of some sensors? I didn't have any code last time I checked on Vida/dice few weeks ago. Actually I don't think I have ever seen the engine check light since I have the car, and I am the original owner.
Another question: is it common for R blocks to have a cracked cylinder wall on stock boost level? I guess running too lean contributed to it.

s140s · Dec 15, 2014

When I was swapping the engine on my R, I undid subframe bolt and then lifted the whole front end with engine hoist. Everything rolled out on the dolly, suspension, trans, axles etc. I then had all the space necessary to separate it outside the car.

CMOD_R · Dec 15, 2014

Wait your not losing coolant and your taking the head off to look for cracks?

contrast · Dec 15, 2014

I lost only a little coolant. Maybe 100ml in a month or so. Three cylinders were cracked

Rmind · Dec 15, 2014

I am not 100% sure I am not losing coolant. I think I did top off once, but it was still above mid level. What would you suggest?

Rmind · Dec 15, 2014

I was not able to get a coolant analysis kit from the local auto parts store.
Here are some pic from the inside of the cylinders:

Cylinder 3 has no sign of coolant on top of the piston. Should I expect this in case of wall cylinder leak, as the autozone sales person suggested?
I would imagine that a small amount of coolant would just be vaporize and not visible on the piston.

contrast · Dec 15, 2014

You need to look at the top of the cylinder. Right where it meets the head. And look at the area that is next to 2nd and 4th cylinder. Sides. If you will. Sorry my english, hard explain

Rmind · Dec 15, 2014

I know that's where I should be looking for cracks, but my camera could not do that, just look straight down. Is it worth trying to get a better camera or would it be hard to see anyway?
Can the coolant test determine if there is a crack of the cylinder by detecting contaminants in the coolant?

contrast · Dec 15, 2014

titan joe · Dec 16, 2014

I'm not convinced that the turbo or the cylinder walls are bad, but I could be totally wrong. Make sure that the piston is not all the way at the top and check the wall sides that are closest to the neighboring cylinders. That's where they crack, right at the top. Looking for hydrocarbons in the coolant would be a sure way to know if you have a leak of any kind between the combustion chamber and coolant.

Rmind · Dec 16, 2014

Can you test for hydrocarbons in the coolant without the engine running? All the test I have seen were perform with the car running.
I have otherwise ordered some mirrors for the camera so I should be able to see the top of the cylinder.

ElementR · Dec 16, 2014

I've peered into my cylinders with a borescope before and you simply can't get enough angle on the scope to see the top of the cylinders. You really need to pull the head to see. Before doing so, I agree that you want to check for combustion gasses in the coolant. You can get such a test kit at your local parts store.

ElementR · Dec 16, 2014

Yes, it needs to run as you need to see the gases reacting with the coolant. If that's not an option... at least you'll have the mirrors.

Rmind · Dec 18, 2014

Any idea what could cause to run too lean without throwing a code? Can the O2 sensor be bad enough to throw the AFR off but not cause an ECL?

How bad is my turbo?

Rmind

spinall4

contrast

Rmind

contrast

spinall4

Rmind

s140s

CMOD_R

contrast

Rmind

Rmind

contrast

Rmind

contrast

titan joe

Rmind

ElementR

ElementR

Rmind

Top Contributors this Month

Recommended Communities