Running with the cam cover off?

[Monkeythree]

Trying to diagnose the rattle which I heard when I got my S2 running for the first time this weekend. It sounded like it was coming from near the centre of the cam cover so I assumed it was probably going to be related to the cam chain and/or tensioner.

I've now popped the cam cover off to have a look and it doesn't look bad at all. Yes the top pad is slightly grooved so I will change it anyway but I'm now thinking there may be a broken valve spring or a ferked lifter which is the source of the noise.

So my question is: how much oil is going to be ejaculated if I run the engine with the cam cover off for a few seconds while I try and identify the source of the rattle?

Thoughts?

M3

 

[Monkeythree]

I've got a video of someone doing just this somewhere, not too bad, just a bit Splattery. Maybe make a cardboard surround to fit around the area to stop the spread? Definitely have a helper on the key to kill it quick if required.

 

[robdimond]

Never done this, but thought about it. I imagine there is a lot of oil spraying about under there...

What colour are the tensioner pads? White=new, yellow=old, brown=any second now...

A very stretched chain will also cause a rattling noise (well it did for me...). You can see that the tensioner is near the limit of it's travel if the top tensioner pad sits completely clear of the body of the tensioner (so that in theory it could be slid off without removing the tensioner assembly).

I'd be interested to see a video if you decide to do it!

 

[graham.webb]

The amount of mess perhaps depends on how the oil gets to the cam? Worth a try?

In another era I had a Vauxhall Chevette (don't ask...) and after sorting a burnt valve, valve adjustment on the that (ohv) engine was hot and running....surprisingly easy, but don't wear your best shirt!!

Also, FWIW I had the chain replaced when the belts were done....my Indy reported some sprocket wear, and as you'll know if you've had bikes worn sprockets tend increase chain wear, leading to broken chain etc.

 

[PAUL RUDDY]

I still have oil marks up the garage wall from checking to see the oil feed to the rockers on a Rover V8 with the cam covers off, not content with testing one side I then checked the other bank with similar results []

 

[T3rra]

Is there any marks from the chain in the underside off the cam cover?

 

[colin944]

Top pad is easy to change. I would change the chain and the top and bottom pad first. Then look for other more sinister things.
Bottom pad is harder to get at and is therefore not done very often and may still be original.
First rule of looking for things Check the obvious first.

 

[Monkeythree]

ORIGINAL: T3rra

Is there any marks from the chain in the underside off the cam cover?

No. That was what i was expecting but the tensioner pads seem to be not too bad. I squeezed the tensioner with my thumbs and it sprung back nicely.

Think i will give it a run in the morning with the cam cover off and see what i can hear.

M3

 

[Monkeythree]

Found a copy of the movie file here:

16 Valve in Action

 

[Monkeythree]

So i decided against having a go with the cam cover off and went straight to changing the cam chain tensioner pads. With the cam cover back on it still rattles like a bastard so i'm going to have to have a go with the cam cover off to try to identify the source. The video suggests it isn't going to be too messy so it's worth it if I can find out what is wrong.
M3

 

[Monkeythree]

Just been reading that the noisy lifters are quite common on cars that have stood for while like mine. Seems that running for a good 40 minutes and an oil change could be all it needs to get the followers to quiten down.
M3

 

[Frenchy]

Top end valve cleaner (additive) is what you want, about £7 a bottle from your local motor factors sorted after pouring in and ran for a couple of minutes []

 

[edh]

lifters can be very noisy if the car's been stood for a long time. takes quite a while to go as well & can be a bit unnerving waiting for it to quiet down.

can you post a video of the noise?

 

[david924s]

My S2 is noisy and always has been it is worse when cold but whereas it used to quieten down a lot after a few minutes running now it is only slightly better. I have had the cam chain, pad and tensioner checked when the cams were out for replacement tappets and a re-time. It was a little quieter afterwards but not much. The guy I use for my car (excellent Porsche mechanic) sugested that the cam journals may be slightly worn but another specialist has looked at the pictures of it stripped and thinks the journals still look sharp so unlikely to be an issue. I am currently preparing to have the head taken off and sent away for new valve guides/seals and re-lapped valves along with replacement of any other worn tappets, with a light skim and good clean up. The head guy will measure the cam journals and if they are worn then it is planned to have them line bored.

I have to say the car has been noisy from day one which was 5 years ago and I have had a lot of investigative work done to try to sort it, so I hope this next phase identifies or at least eliminates a possible cause.

For your car it may be worthwhile chaning the tensioner pads as you say and giving the car an engine flush and oil change to see if it helps.

 

[Monkeythree]

Additive, run for half an hour then oil change is the route I'm going to go down. I might even repeat that cycle twice to give the followers the best possible chance of being refreshed.
A job for Saturday morning!
M3

 

[Monkeythree]

So, after a dose of Wynns tappet restorer, an oil change and a second dose of tappet goop, my top end is now A LOT quieter. But now I've noticed that that it sounds pretty dieselly at tickover and it's not really as smooth as I was expecting when you rev it up a bit. So further investigation is needed to get it running nice and smooth.

The good news is that while I had it up on the ramps I was able to have a decent look around the underside of the car and (apart from the sills which I knew about) the shell is really solid. The fuel and brake lines are rusty and the dampers appear to be the originals so those will need changing but I'm somewhat relieved that the basics seem sound.

M3

 

[zcacogp]

Mr Monkeythree,

Just come across this thread having read your PM!

Sounds like you have got to the bottom of the noisy lifter issue - well done. There is further gain to be had once you run the car on a regular basis (although I know you aren't going to do this). Different grades of oil can help or hinder the noisiness as well - what grade do you have in there?

Another thing to bear in mind is that the injectors can be very noisy. I don't know why, but I do know that every time I have asked anyone about this the answer is always "Well you can change them if you want, and the replacements may be a bit quieter, but there's nothing wrong with the existing ones apart from a bit of noise".


Oli.

 

[Monkeythree]

Dear Mr Slippers,
Todays lubrication was 15W 40 Castol GTX Magnatec. What went in was a lot less black than what came out!
Was planning to take the injectors out and get them on an ASNU as soon as possible. Won't be this weekend as I've already spent all afternoon today on the car and I won't manage any more time outside tomorrow without protestations from Mrs M3.
It's quite interesting that with each noise removed, another one is revealed. I think I am going to be playing "chase the rattle" for several weeks yet.

M3

 

[zcacogp]

Hmmm. That's an oil that should be OK, but you could try something thicker (that hangs around in the lifters a bit longer) if you wanted. Is the car drivable at the moment? If so, does it get quieter after a reasonable run? (If not, how about leaving it to idle for a while and seeing what it's like then).

I know it's a bit of a hand-wavy comment, but 944's seem to run better, more smoothly and quietly when they are used frequently and hard. Your chasing of odd noises may just be a result of the car sitting still for a long while. I seem to recall that your long-term plans for the car involve storing it while you get the bodywork sorted out. If this is the case then I'd be tempted not to worry too much about odd noises from the engine; if it works OK then don't fuss about the details until you re-commission it for regular use. Any odd noises resolved now may yet re-appear if it is stored again for a few years.


Oli.

 

[Monkeythree]

Car is drivable but not road legal due to no MOT due to all the rusty bits and various other niggly bits. It's been running for around an hour today between idle and 2000rpm before and after I was changing and treating the oil. I think the car has been standing for a long time and just getting it running and refreshed with a basic service has made it run MILES better than it was when I got it a month ago.
Plan of attack at the moment is for me to resolve all the mechanical maladies myself first and then bung it in to a local bodywork specialist to get the welding and paintwork done. I could do the welding and paint myself as I have the kit and the experience but I just dont have the time.
What I've achieved today is to establish that the condition of the shell justifies the investment in sorting out all the things that are wrong with it. I've got a kit car on ebay at the moment and as soon as I get the cash in from that then I'm going on a spending spree on the 944!

Cheers
M3