MTemp

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 (UK available). What do you think?


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

MAGK944

This is normal behavior for the lifters if the engine hasn't been started in a while, it's likely that oil has drained out of a few lifters that is causing that noise. The car really needs a good long drive and it will sort itself out.

Don't use any flushing oil just change the oil and filter and drive it. These cars hate short trips or to just sit around.

MTemp

Thanks Mike,

Will do as you suggest, and hope it's that simple!

Mick

lart951

just do the ATF fluid trick it will solve noise from the lifters

https://rennlist.com/forums/944-turb...il-change.html

fejjj

I have had this issue for awhile.

Thank you for the tip LART!!

mikey_audiogeek

Also run a bottle of Redline fuel system cleaner in your gas tank. My experience is that this helps with noisy lifters.

lart951

How is the fuel sys cleaner going to help with noisy lifters? Perhaps you have confused the noise from the injectors which happen to be loud and sometimes similar to the lifters, but there is no way the fuel cleaner is going to fix, reduce, help with lifters noise.

CO951

I 2nd the tranny fluid before changing oil. I had a sticking lifter several years ago and did this. It pretty much got rid of the problem right away. I did at my next oil change, too and haven't had the problem again for several yrs.

mikey_audiogeek

I should have given the full explanation. Dirty injectors cause fuel dilution of the oil which contributes to varnish formation. Might also explain the reliability issues with the OE replacement lifters...

MTemp

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 TIPEC in the UK 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

ealoken

How much noice is normal? mine is realy making a loud ticking..

ealoken

Mine is very like this.