Engine condition after 26yrs/70k on my 944 turbo

[Paul 290T]

Hi, My '86 turbo was still running on its original head gasket and all but a few of the cooling system hoses. Although it was running fine I asked Redline Racing (my Indy) what they thought the condition of these components would be like. A few weeks earlier they'd changed the CHG of another '86 turbo which also had its original gasket fitted. This one had large sections of gasket missing between the coolant passages and was in a mushy condition.

So I decided to have my cars CHG replaced as a precaution. I also asked RLR to check some other components whilst they had the head off and access was afforded into usually hard to reach areas. Here's a summary:
Head gasket was worse than the other '86 turbo's. They showed me a photo and it looked the sail of a battleship that had not fared well in the battle of Trafalgar. It too was mush and could be scraped off without the use of tools.
Cylinder bores, very good. I've run it on Mobil 1 Motorsport 15W50 since 45k and it's now done 70k miles. The valves were also fine.
Valve seats were worn slightly. These were re-cut and hand lapped, plus new guides were fitted.
The original radiator was weeping slightly at the core to side tank flange. So it was replaced too.
Nearly all coolant hoses were found to be very hard, hardly gripping the tubes they were clamped to. So all hoses made accessible by head removal were changed. Some vacuum hoses were also changed whilst access was good. A leaking heater control valve was changed. RLR reckon 95% of all hoses are now new. I'm impressed with a coolant hose that does not give up after 26years, but not changing them was I feel tempting providence.

Porsche were able to supply every hose, only one being on back order. Excellent service for a car of this age.
The starter motor was found to be full of dirt and rust. It was stripped overhauled and refitted.
Thought you'd be interested and that these findings might help in planning your own cars future maintenance works.
Regards Paul

 

[Mike_Pollock]

Thats a great report, reminds us all just how old the cars are and that they are 25 years old BUT still running on original bits like the hoses and head gasket.

Thanks very much for posting.

 

[simkin911]

Thanks for that. Interestingly, HG on my restoration turbo was recently changed by Sulzeruk ('91 plate, 149k on the clock) - it was certainly showing some signs of rot but it wasn't anywhere near as bad as you describe.

You should really have finished off your post with a few photos BTW! []

 

[ukmastiff]

I'd be genuinely interested to know the bill !

Glad you're giving your car some love


Cheers

Mas

 

[George Elliott]

Paul,
I would say your engine is now of better quality than 80% of the brand new engines in your local OPC.
I doubt very much that a 70k miles 951 with a good history and regular Mobil 1 needed valve guides, but hey it keeps unemployment down.
My own CHG was rotten and actually failed on the rear most cylinder some years back. Did you fit a Cometic? they are Aluminuim as opposed to the steel plated standard fit Victor Reinz thing which rots away.
Good luck with it
George
944t

 

[colin944]

I found this really interesting as I have just pulled the engine out of my S2.I am going to do all gaskets inc chg and check everything else while I am in there. I will post pics as I go .

 

[Paul 290T]

Hi,
Thank you all for the interest shown in my write up. Here are the answers to your questions.

The cost, which also included, in addition to what I've already listed, the following:

head skim, new cam and balance belts, new CV boot, new battery, new Goodridge brakes hoses all-round (which involved many hours freeing and repairing a stripped bleed nipple bore), brake fluid, new coolant, oil and filter, new air filter

came to"¦"¦"¦£2,700.

This, although I consider a good price, is still a lot of money. I consoled myself by remembering the whole maintenance cost for the year before only came to £200.

I decided, with RLR's agreement, to fit a standard Porsche CHG. From the research that I made I decided the Cometic required really flat mating surfaces to seal properly and the Wide Fire was more suited to O ring conversions. Besides I knew of two 944 turbo's that that ran 25yrs on a Porsche CHG. I doubt my car, as good as it is, will ever need another CHG after this one.

I've contacted RLR to see if they still have the photo of the rotten CHG, I'll post it if they can find it. The service history includes the three yearly coolant changes throughout the life of the car. It's always been serviced by specialists or Porsche, so I imagine the correct coolant has always been used. I don't think CHG rot (as in my car) is mileage related, I'd say it was age that did it in. Hence your 149k '91 turbo CHG being in better condition.

I agree, there's no way modern Porsche engines are going to last like those fitted to our cars. Though I've not seen any rusty Boxsters or 996's, so maybe the bodies are good.

The valve guides were only about £16 each. So in the grand scheme of things it seemed daft not to have them changed while the head was off being skimmed and having the valve seats reground.

 

[George Elliott]

Good to hear of a car being well cared for Paul, no expense spared for sure. Pity the head got skimmed as it affects the timing and compression, and as it had not warped following an overheat it was not necessary. Hopefully they only charged you for it but did not skim it. Your gasket will last around 6 years from my experience on 4 different turbos.
I found Promax very good for sound experienced advice on these cars, you might consider trying them for a second opinion if you have other work planned.
George
944t