Clacking Noise from Driver Side Under Valve Cover

GT4Lyfe

Member
Feb 21, 2021
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PA
Hey I have a 97 GT no major work done that I know of, bolt ons. Always taken care of, oil changes, spark plug changes, etc. Never redlined or ran hard (3500-4000) shifts tops.

Pulled out of a store last night and heard the thrashing. It sounds like a rock bouncing up and hitting the driver side valve cover. I can feel the vibration of the noise through the oil cap and the valve cover when on. I haven't pulled off the valve cover (I heard it's tough) but I listened close. It doesn't appear to be timing chain area. What do you think this could be? And is it the end of it all now? I don't have time to do work myself past basics and not super flush on cash. I'd like to save the car though. The idle appears fine, exhaust smoke seems the same (there is a more oily / exhaust smell) under the hod though. It's even gone away for around 5 minutes once, but then came back. It literally sounds like a rock or two underneath bouncing into the cover. No overheating that I can see, all fluids look fresh (oil is fine on dipstick at least).
 
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Never redlined or ran hard (3500-4000) shifts tops.
That's not good on it either. :shrug:

Pulled out of a store last night and heard the thrashing. It sounds like a rock bouncing up and hitting the driver side valve cover. I can feel the vibration of the noise through the oil cap and the valve cover when on. I haven't pulled off the valve cover (I heard it's tough) but I listened close. It doesn't appear to be timing chain area. What do you think this could be? And is it the end of it all now? I don't have time to do work myself past basics and not super flush on cash. I'd like to save the car though. The idle appears fine, exhaust smoke seems the same (there is a more oily / exhaust smell) under the hod though. It's even gone away for around 5 minutes once, but then came back. It literally sounds like a rock or two underneath bouncing into the cover. No overheating that I can see, all fluids look fresh (oil is fine on dipstick at least).

If you're not able to dive into it, take someplace and get it looked at. It's not driveable IMO, until that is complete.

I have suspicions as to what it could be but that's pretty useless. :shrug: You have to open it up.
 
What are your suspicions? I'm looking for input .I will definitely get it opened though. I do push the car somewhat I just meant I don't redline it daily (or ever) and no power shifts. Just 1-2-3 granny shifts to WOT at 4000+ rpms and sometimes stand alone revs.
 
If it was summer I'd probably take my tool set out and get the driver side cover off. Is it really that hard to do with basic tools? If I can't muster the strength I'm going to get it looked at tommorow or tuesday hopefully. No driving. I did drive home the other night but kept it low revs and slow and it seemed to make it.
 
If it was summer I'd probably take my tool set out and get the driver side cover off. Is it really that hard to do with basic tools? If I can't muster the strength I'm going to get it looked at tommorow or tuesday hopefully. No driving. I did drive home the other night but kept it low revs and slow and it seemed to make it.
It doesn’t take much to get the drivers side valve cover off. Just a bunch of 8mm bolts. Your plug wires might be in the way, otherwise there isn’t anything else to it.
 
The only time I have had this sort of thing happen was on an older pushrod engine when a rocker came loose. Something is not where it should be, and it's definitely a serious issue. People change heads and such with the engine in the car, so I would assume it wouldn't be that bad to pull the cover.
 
Thinking it might be Timing Chain or in that area...what do you think labor is to have it done with someone average rate maybe? And what else is recommended while this is done? Water Pump? Gaskets?
 
It could be the timing chain tensioner, they operate on oil pressure, and are a known problem. Easy enough to get to, but you have to take the front timing cover off. 2 bolts on the tensioner. Def doable in the car, but easier if the engine is out.
 
Wise to put new water pump and gaskets in or just water pump? Since the front would be off... Do you think since it hasn't been driven it should be ok (i'e no damage)?

Also, what do you think labor wise?
 
Wise to put new water pump and gaskets in or just water pump? Since the front would be off... Do you think since it hasn't been driven it should be ok (i'e no damage)?

Also, what do you think labor wise?
Well the front cover doesn’t have to come off to change the water pump, so I guess it depends on the mileage.
I don’t have access to all data anymore because I work on planes not cars, but I can’t imagine it be more than prob 6 hours. Anyone out there know what the book time is for it?
I will say this, if it’s the tensioner, you don’t want to drive it. If it’s not keeping tension, the chain can jump teeth, and that’s a much bigger much more expensive problem.
 
How would I know if the chain has jumped teeth at all? The car doesn't seem to over heat or miss idling besides the noise, the only thing I've noticed is more exhaust type smell under the hood and the oil got a bit darker brown (maybe the level dropped a bit also).
 
Ok this is wierd. I got the belt back on and all cleaned up, fired her up, let it idle and messed with some stuff and got the noise to stop consistent for 10-12 minutes warmed up well. I turned it off, back on and it was fine, no noise. Idled alot, then took it for a few short spins around the block. Call pulled smooth and no bucks or misfires that I could notice, no smells. The noise slightly came back after returning and idling but I managed to stop it by hamering around a bit around the injectors, valve cover, etc. Is this something injector or spark plug related? I coulda swore I saw a spark down in the one spark plug hole around the wire. The car drives too smooth imo to have something wrong. It just doesn't make sense. The noise came back a bit momentarily but I was mostly able to stop it or it stopped on it's own. Spark plugs are dirty - they had oil residue on them due to valve cover. Would a timing chain really do that?

I've already eliminated it being ANY of the pullies, so it's not that.
 
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rarely do engines fix themselves and the shoemakers elves just do footwear ... sad but true, you will have to examine the mechanicals to actually locate the cause and only then can you determine the good news bad news or cost ... everything else is just a guess
 
Ok this is wierd. I got the belt back on and all cleaned up, fired her up, let it idle and messed with some stuff and got the noise to stop consistent for 10-12 minutes warmed up well. I turned it off, back on and it was fine, no noise. Idled alot, then took it for a few short spins around the block. Call pulled smooth and no bucks or misfires that I could notice, no smells. The noise slightly came back after returning and idling but I managed to stop it by hamering around a bit around the injectors, valve cover, etc. Is this something injector or spark plug related? I coulda swore I saw a spark down in the one spark plug hole around the wire. The car drives too smooth imo to have something wrong. It just doesn't make sense. The noise came back a bit momentarily but I was mostly able to stop it or it stopped on it's own. Spark plugs are dirty - they had oil residue on them due to valve cover. Would a timing chain really do that?

I've already eliminated it being ANY of the pullies, so it's not that.
It makes sense if you have an injector that is clogged or misfiring. The noise you could be hearing is lean combustion.

Wild Ass Guess based on your description.

You might pull and inspect each injector. It is hardly worth doing however unless you also plan to rebuild them and that's hardly worth doing unless you plan to get them cleaned and flow tested.

How much would all of that cost? I don't know. You should call around your area for pricing.
 
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I'm still at this. I've been driving around - no miss, no overheating - does feel a bit underpowered at times but I think that may be because of spark plug wires or coils or both. I put eight new plugs in gapped correctly. I'm going to try for a different set of coil packs first, then possibly wires. But I AM going to tackle the driver side valve cover - wish me luck gentlemen. What exactly should I look out for or look to inspect? I'm not going to attempt to run the car without the valve cover (too messy right?) so need to know what to look for with the cover and the car off.