TheSamba.com :: View topic

Fri Mar 28, 2008 11:57 am

OK, I'm starting to loose my mind...

I have an 86 Syncro that has, what sounds like, a lifter tapping on the driver's side. Problem is it doesn't act like a collapsed lifter... It only starts tapping when the engine is warmed up to normal operating temperature. When I start the van in the morning it purrs like a kitten.

I have springed pushrod tubes installed so last night I decided to remove all four lifters on that side and totally clean them out to eliminate this tapping noise that has been haunting me for almost a year. (Tried the marvel mystery and valve adjustment before the winter hit).

Here they are all disassembled and cleaned. The "S" stands for my spare lifter and the numbers correspond to the order they were in when removed (1 being closest to the nose of the van and 4 being closest to the rear).

This is the lifter that was in the number 1 position...

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I'm assuming the 3 gouges on the top are from the pushrod tube smacking into it?

I assembled the lifters back together and switched the spare for the number 1 lifter and preloaded them. They were all nice a tight and behave as a normal lifter should.

I put everthing back together this morning, adjusted the valves 1 1/2 turns past contact and low and behold the tapping is still there.

Is there a valve issue here?

Before I turn to the bottle does anyone here know what the hecks making this noise?

Fri Mar 28, 2008 4:26 pm

Sorry about the double post...

Fri Mar 28, 2008 4:40 pm

Mathew Zelezen wrote: I have an 86 Syncro that ...only starts tapping when the engine is warmed up to normal operating temperature.
You have a 2.1. When a 2.1 wears out, the rods start making noises when hot. They make noises because there is not enough oil pressure to float the rod bearings. These noises are death rattles. DO NOT DRIVE.

Go read the stickies about measuring your oil pressure. Make sure you got good oil pressure.

Also, noises can fool. You sure you have the correct side. Have you ever hear real a real good lifter noise in real life from a Vanagon? They are quite distinct.

You could have a loose or worn something in the head on that side. Are your pushrods all still straight?

How do your adjusters look? You need to be sure they don't have flat spots.

I am sure there are more guess' but I think I have guessed enough!

Good Luck,
Walt...

Fri Mar 28, 2008 4:58 pm

Well Walt, now that you mention it... one of the pushrods was bent when I took it out. Forgot to mention that.

The wear holes on the top of the lifter seems to point to origin of the noise I'm hearing. It looks like there is some play somewhere when the engine is hot and the pushrod is not tight to the lifter. It then beats on the top of the lifter.

Oil pressure seems to be up to speck. No lights or buzzers and it checked out when I replaced the gasket to the oil pump this past summer.

Fri Mar 28, 2008 7:03 pm

Lets remember that just because the Oil light does not come on, does not mean there is low oil pressure. Don't be a cheap freak, check it with a guage. The oil pressure is good according to the book? The pushrod is O.K? I would look in the direction of a cam lobe or bad rod.

Fri Mar 28, 2008 7:31 pm

George, i think you misread...
" ... one of the pushrods was bent when I took it out."

So what typically bends the pushrod tubes folks?

Fri Mar 28, 2008 7:55 pm

Stuck valve. The intakes seem to be notorious for this. But it looks like your trouble was with #1 exhaust. It can be intermittent.

Didn't you index the pushrods to the lifters? I'll bet your bent pushrod was riding on that chipped lifter. A valve may have stuck open, which let the pushrod lift out of the lifter cup, and then it caught on the rim of the lifter and chipped it. Looks like it did this several times. It could be that the valve is sticking some once it gets hot.

Take off the rockers and check the valve tops with a straightedge. Pay particular attention to that #1 exhaust. Then get it hot 'til it's clicking audibly, shut it down and quickly tear off the rockers and check them again.

Fri Mar 28, 2008 8:15 pm

You could also remove the valve cover when the engine is hot and let it idle and take a look at what is going on in there while running. Be careful, the oil sprays a bit when doing this and it is hot. I have "Used" lifters if you need one to get by with for the hell of it. pm me if need be.

Fri Mar 28, 2008 9:17 pm

The bent pushrod was from the number 3 position.

Sounds like a stuck valve with the possibility of others on the way.

My heads started leaking this winter and I plan on changing the gaskets and checking out the condition of the heads... better start saving my nickels and dimes.

Thanks all!