cars3

Hi everyone, I've got a 91 Z-28 with a 350. It's basically all stock except for k&n and flowmaster exhaust. My question is about 1 month ago, my motor started making a ticking noise, and as the engine revs faster so does the ticking noise. I thought it was the cat. but when I opened the hood it sounds like it's coming from under one of the valve covers. About 2 months before this problem all the anitfreeze went into the crankcase. Well I fixed that problem with some leak sealer that the local chevy dealer recommended it fixed the problem. Could my new problem be related, or is it something completely different. The car has not left my garage since this has happened. I did take of the drive belt to rule out any accessories. Thank's for any and all help.

z28motorsports

i would say it is the lifters........and when you say all the coolant went into the crankcase.......did it run hot ? sounds to me you have an intake gasket leaking coolant or a cracked manifold base.

jayman350

the ticking is most likely the lifters, you can get a set of rocker arm clips that will allow you to adjust the valves to get rid of the ticking.

i would check the head gaskets, intake gasket, and anything else you can find in that area to find out why you dumped coolant into the crankcase..... and i HIGHLY doubt that some leak sealer will do the trick, you are most likely looking at replacing some gaskets on your top end

cars3

A friend of mine also said it was more likely the lifters. I'm sure if you replace one, you replace them all on one side right? Or do them come in a full set of 16 and do both sides.

jayman350

you replace all 16 of them, otherwise you will get uneven wear on the camshaft lobes

its a fairly straightforward swap, take off the valve covers, remove rocker arms and pushrods, take out old lifters, put new ones in, put back together

iirc you have to soak the new lifters in oil to get them loaded up on the inside, its a 2 or 3 piece lifter w/ the oil acting as a cushion

cars3

I guess it would make sense to replace all 16. Thanks for the tip on the oil. I've rebuilt motorcycle and snowmoble engines alot, but never really got to deep into car engines. I have owned 4 3rd gens ( I have 2 now) and I've got a 4th gen, and have never really had to work on the engines. I would say I've been really lucky. It's nice to know that there is a place on the internet to go and talk with people with alot of knowledge. I'll take a look at the lifters in about a week (I work alot), and I'll post the results.

Tex95Z

is this a TPI motor? or did you carb it? If its TPI it could be the injectors ticking.

cars3

It's a tpi motor and all stock. The injectors were replaced about 3 years ago by a chevy dealing totaling $1500. They gave me a break because I bought my 2001 camaro ss brand new from them. They cut $300 in labor. They told me that they are under warrranty for life as long as I own the car.

z28motorsports

you will need to make sure which lifters you have..........my 92 rs had roller lifters ,some still have flat tappet...........even though i'm sure yours will have roller,you still need to be sure........and neither lifter (flat tappet or roller) will interchange.

IROC-T

Before tearing down, you should make certain it's NOT an exhast manifold gasket (or donut). They can make a ticking sound when they first start to leak.

84Camaro_L69

I know my car is carbed, but I had a similar ticking that I could only hear from inside the car. One day the 23 year old intake manifold gasket blew and dumped coolant into my oil, onto my exhaust manifolds, etc.

After the intake manifold was replaced my ticking went away. For months I feared it was lifters or rods, but I couldn't hear it from under the hood.