engine vibrations

**pk222** · 01-21-2010, 11:17 PM

Hey guys, I've got a high milage 98 z28. Its had a small ticking since I bought the car 2 months ago but I haven't had the chance to get it checked out. In the last couple days it got louder. I think I singled out the vibration to be the engine considering I can be in drive and feel the vibration to it being gone when I put it in neutral.
The noise sounds like it could be either the timing chain, water pump or something else in the bottom front of the motor.
Does anyone have any idea what this could be? I'll have the car in the shop as soon as possible but most are close from snow.
Thanks in advance

**red99camaross** · 01-22-2010, 06:23 AM

check your belt pully tensioner if its out of allignment by up to a millimeter it will cause unwanted vibration and isn't likely related to the ticking noise check the tensioner for movement while the engine is at different speeds and or under load like the air conditioner pump kicks in. as far as the ticking noise is concerned look for an exhaust manifold leak that would be the best case scenario.

**shady milkman** · 01-22-2010, 06:30 AM

our cars are known for ticks and so forth... look at possibly your plugs or wires being loose etc. check your rocker arms ..make sure they are in spec in terms of the lash. Also check your pushrods and so forth...is your car a a4 or m6 , mods or stock.

as for the vibration..i'd go with red99 ...also get your mounts checked.

**tep98ws6** · 01-22-2010, 06:40 AM

Originally Posted by shady milkman

our cars are known for ticks and so forth... look at possibly your plugs or wires being loose etc. check your rocker arms ..make sure they are in spec in terms of the lash. Also check your pushrods and so forth...is your car a a4 or m6 , mods or stock.

as for the vibration..i'd go with red99 ...also get your mounts checked.

i second this.

**red99camaross** · 01-22-2010, 06:56 AM

thanks for the bid of confidence e1 sometimes the root cause of belt pully tensioner failure can be but not always a pressure imbalance in the air conditioning pump have your system pressure checked. I also reccomend changing your rad cap to keep your coolant pressure balanced to extend water pump life. the rad cap is commonly overlooked and in my opinion should be changed once in a while.

**pk222** · 01-22-2010, 09:30 AM

Whoever moved this to general help, thank you.
I'm new to ls1's and chevys in general but the ticking doesn't sound like something that would be normal. It sounds like its in the bottom front of the motor.
My car is an a4 and the only mods I know of are k&n and flowmaster catback.
I was told that the engine mounts were recently replaced with urethane ones but we all know how trustworthy people are when your buying their car.
A friend who is a mechanic heard the noise and thought it could be the timing chain but I was told if the timing chain was going there would be no noise before it was too late.

The ac doesn't work, the old owner was replacing the battery and made contact from the battery to the metal line coming out of the ac condensor and it burned through I guess.
As soon as I find the noise and vibration I'm flushing the cooling system and getting a new cap and thermostat.

**tep98ws6** · 01-22-2010, 09:40 AM

they tick ... a lot, esp on cold start ups. it's an extremely noisy valve train

it's more than likely a top end noise, like shady said - pushrods, rockers, ect - all of which are pretty easy to check out ... it's not a cackling sounding noise is it?

**pk222** · 01-22-2010, 09:52 AM

It does sound like cackling.
Its pouring rain and I don't have access to a garage. The soonest I can get it into a shop is monday. So I'll let them pull the valve covers if they need to but I'm just trying to narrow it down so I can brace myself for however bad it could be. I'm trying to borrow cars wherever possible because I don't want to make whatever it is worse and possibly mess up anything else.