Porsche Enthusiasts Club Forum

Hello all,

Just want to check my thinking and proposed plan of attack before diving in...

Scenario: 1990 944 Turbo owned about a year. Only done 24k miles when bought having received lots of tlc (and cash) from PO. Done about 5k miles (inc. two European hols) in the past year with no issues. It was serviced prior to purchase and I planned a service in a couple of months before using regularly again. Has been garaged since early Nov. Had to move it out to access some stuff yesterday, started fine and I left it idling for about 5 minutes then shut down. About 2 hours later when I came to start it to put it back in, it had what I would describe as a 'noisy tappet'. Increases with engine revs. Using a screwdriver to my ear it is from No.4.

Now I understand (I have restored a couple of 911's from scratch but have no mech experience of 944's) that these engines have hydraulic valve lifters and these do not need adjusting, but do need oil pressure and the supply port is prone to blockage. Oil pressure on the gauge is normal (4-5 bar when cold dropping to circa 3 when hot). Given the engine went from 'quiet' to 'tapping' quite loudly so quickly I'm reasoning this cannot be a shot rod bearing or worn cam lobe or anything equally catastrophic (please!).

Given an oil change is (over)due then I thought I'd try that first. I have read opposing views on the benefit of adding a flushing agent as well (Forte or similar). What do you think?
I use Miller Classic 20w 50.

If that doesn't work then I suppose the next step is to remove the cam cover and check the lifters manually. Agree? Any tutorial anywhere on specifically how to do this? Any special tools needed?

Any other checks I can do?

Any help appreciated. Thanks
Mick

Such little use is almost guaranteed to give you a noisy tappet as the oil will have drained out of the head while it was sat still for months on end. Add to that the fact the oil change is way overdue (Turbos should have oil changed every 6 months no matter the mileage) and I think thats what your problem is. Weird that it was quiet when you first moved it out of the garage though???

Stick some fresh oil in and drive it more often and you should be fine, its one of those niggly little things that chronically low mileage cars often suffer from. Consider using an ester based oil as these are claimed to have 'magnetic' qualities so a film of oil surrounds your metal bits for longer when not in use

Thanks Paul,

Hope you're right!

To be honest it might have made it when I moved it out but then my mind was elsewhere with the list of things to remember to do when it was out of the garage.

Any views on the use of flushing agents (Forte advanced seems to have good press in some quarters) when I change the oil?

Mick

I have used Forte engine flush 3 times now on my 944 s2 and only average 3 thousand miles per year. This has quietened a noisy tappet.

My oil to look at is not very dirty after 3 thousand miles but on draining after a flush it is very dirty.

I know many are not convinced but I am, and one of the finest specialists for 944 cars in the country offers the forte flush on its servicing menu.


Regards

Mark

I switched from 20W-50 to Millers CFS 10W-50 and the car is much happier on it. Like you I occasionally suffer with a sticky tappet but if left idling for 30 mins the noise disappears and the car runs sweetly.

20w50 seems way too thick for a UK car - particularly in winter.

I did have a stuck OPRV (stuck closed - with spectacular results..) not long after an engine flush - may be coincidence, or may have been a bit of gunge dislodged by the flush.

I would do the oil change and see if the problem persists. If it does check out Forte Top End Treatment

First of all my thanks to all who responded - the problem is now fixed, at least for the moment. I have not ad an opportunity for a long run yet.

After a lot of consideration of the response here, on Rennlist and reading up a bit I decided the low mileage from new, and the relative inactivity over the 5 years before I bought it, I decided to use the Forte Advanced flush before changing the oil. While the oil was black (isn't it always) there was no more crap in it than usual when I drained it, I'd say.

Anyway the lifter seemed to clear itself while the car was idling/warming with the flush in the engine before I changed the oil, so that was a good sign! I replaced the filter (Porsche) and refilled with Mobil Super 2000 10w-40.

Again my thanks - I'll be more diligent in regular use and oil changes in future.

Mick