fischer1

I love this vehicle. A couple issues, but nothing worth mentioning. Lately I've been getting the low coolant warning while the coolant level is fine. Now, though, the coolant has turned milky and of course I suspect a head gasket. The oil is clean and operating temp is perhaps 5-10 degrees higher. I wonder if this happened because sometimes it stays in gear revving at or near redline when I'm hard on the throttle and then let off, it doesn't always upshift. That has happened since I bought it with 50k miles on it. Now it has 85k, most of that rural highway at high speeds. I live in the middle of nowhere and can often drive as fast as I want...which is pretty fast. Unfortunately the nearest Porsche dealer (Annapolis) is 100 miles away
Anyway, I'm thinking of tackling this job myself. Usually a couple of special tools will be a part of the process.
My questions is: Has anyone here on Rennlist done this job before and have any advice? Where to get the service manual or anything else would be much appreciated.

Cosmo Kramer

Are you talking about pulling the heads? I'm not sure, maybe try the 955-957 forum and maybe get some guidance there.

If you have milky coolant I would stop driving it now, as engine oil is loosing its ability to lubricate when it turns into a milk shake.

The transmission shifting is normal if its in sport mode.

Good luck!

deilenberger

Don't immediately assume head gasket. There is another spot that the oil and water are in close proximity on the V8 engines (and I think the V6..) There is an oil to water heat exchanger on the front of the engine. It isn't a common failure point, but it is a possible failure point.

How to tell? Maybe someone has a good idea. If coolant is leaking into a cylinder - the carbon on the piston crown will be shocked off, and the spark plug will also be spotless. If exhaust is leaking into the coolant - use of a freon leak detector will reveal it - held over the open coolant reservoir. But oil to coolant? Dunno.

Head removal requires quite a number of special tools, including an engine lift that fits under the engine and transmission, since they have to be dropped to get the heads off. They come out as a unit under the vehicle which is up on a lift. It's a bit more complicated than the days of old American V8's in huge engine compartments with room to work.

Good luck with this - and please keep us up to date on what you decide to do.

r553

There is a tester that looks for combustion products in the coolant you might try that first.

https://www.cpooutlets.com/uview-560000-combustion-leak-tester/uvwn560000,default,pd.html?ref=pla&zmam=31282435&zmas=47&zmac=722&zmap=u vwn560000&gclid=Cj0KCQiAkZHTBRCBARIsAMbXLhG2wegmr8Z7gOE-hk49_u0wzQlpLQKGdcALwxaOiRe8NdSf-m8lpWsaAmXvEALw_wcB

If there are no combustion products detected that points to the oil cooler. It can be pressure tested at a Porsche specialty shop that has a test rig.

deilenberger

Snip of some photos/video links..I would just comment that if the leak is a high-pressure oil passage leak going up to the head, leaking into the cooling system because of a defective head gasket - and not a cylinder leak into the cooling system - there will be no combustion byproducts to detect in the coolant. Combustion leaking into the cooling system is probably the more common type of leak since the cooling passages around the cylinder bore run close to the bore - it's not the only type of leak that can occur.

That's where the quandary is - and I'd suggest testing the oil cooler test before even considering a head gasket replacement, especially since there is no way to determine IMHO - which head has the problem. One might even consider the replacement of the oil cooler instead of pressure testing the old one, since the cost of the cooler isn't horrendous (there are aftermarket replacements available) compared to the cost of the labor to R&R one. That of course presumes you're paying someone to do it..if you DIY - then it might be advantageous to have it tested (and reinstall it if it's good.)

fischer1

It is now at Porsche of Annapolis, it was suggested by the service writer that- because a blown head gasket would be uncommon and that the oil cooler is liquid cooled- there may be a less tragic cause.
This, I assume, is the oil/coolant heat exchanger described above by deilenberger.
I was incorrect in saying that the temp has never risen, it has remained 201 F. The oil temp runs in the 204-210 range, but I did not monitor that prior to this issue surfacing.
I am expecting the assessment later today and will update.

fischer1

Thank you for your input on this. Would you know where one would spec out the proper aftermarket cooler? Just to be ready when Porsche comes back with a high quote.

CAVU

AllDataDIY has a good set of instructions for swapping out the oil cooler. It is mounted in front of the upper oil pan. The coolant lines are pinched closed during removal. If you have PDCC, the holder is lowered.

Oil cooler for 2011 S retails for about $450 but you can order it online from Porsche Annapolis for less. You will also need two seals. https://parts.porscheofannapolis.com/about-us

Insure that you are ordering the most current part number since Porsche has rolled the part number.

Frankly this looks like a 1.5 hour job on my back, plus at least one oil change, possibly two. It would be worth it to have them do it... IF that is the problem...and I hope it is that simple.

deilenberger

I'd suggest viewing: https://rennlist.com/forums/cayenne-...t-v8-only.html - by user Dilberto (AKA Zach) about replacing the oil cooler on his 955 V8. He mentioned his source in the article. Dunno if the coolers are identical or interchangeable, but it should give you something to start with.

As far as doing it in 1.5 hours - I think that's rather optimistic, or someone is a much faster mechanic than I am. It's going to involve refilling the coolant and changing the oil once or twice - and just those jobs could exceed 1.5 hours of my time. Zach details the job quite well and points out problems he encountered doing the job. I would be surprised if it is much different on a 2011 CS..

CAVU

I could have been clearer. The 1.5 hour reference is purely the hours I estimated for the cooler R&R. The coolant refill is not an issue. Per the All Data, the two coolant lines are pinched off just about the cooler. Minimal loss of coolant.

Completely agree that more hours will be spent on the oil changes, which I did not estimate.

stv951

Any updates on this issue ?

RAudi Driver

It's been 4 years, you can assume that they aren't coming back here. Check the yard.

stv951

i know. Am just facing a similar issue and reading opinions about it but there is not much on the web about this problem

maybe someone else has faced and solved this