Lifters

MAZVER · Post by **MAZVER** » Tue Jul 14, 2009 6:45 am

Got a problem with noisy lifters (I think) in my 3.5rv8. The noise is fairly non existant when cold and becomes very prominant when hot, sounds even around the rocker covers. Im guessing that the lifters are gone, i think the cam is fairly new and i have done bugger all driving on the motor. So theoretically if i replace them that should fix the problem?

Also engine produces a bit of smoke (oily smoke) out breathers from rocker covers, bottom end is fresh and heads have been dipped, carbon removed valves lapped in ect. Not sure about stem seals. Any ideas on most likely cause? Possibly rings havent bedded in properly?

Any help would be greatly appreciated
Cheers

ChrisJC · Post by **ChrisJC** » Tue Jul 14, 2009 7:27 am

It's pretty easy to inspect the rockers & rocker shafts, so I would definitely start there.

However, were new tappets fitted with the new cam? If not, you could have a knackered cam / or tappets.

Chris.

MAZVER · Post by **MAZVER** » Tue Jul 14, 2009 7:55 am

Thanks for the reply Chris!
I purchased the bottom end as a rebuilt unit but did not include lifters so the ones i have used are from another motor i did not check the preload on them (not something i have done before). Had a good look at cam before putting motor together and couldnt see any signs of wear it looked in good nick.
Will have a look at rocker gear and shafts tomorro, should i remove shafts and slide rockers off inspecting for wear and excessive clearance between shaft and rocker?

ChrisJC · Post by **ChrisJC** » Tue Jul 14, 2009 10:39 am

Cams might not look worn, but they are accurately profiled to turn the tappet a bit each time the lobe goes past the tappet.

I would definitely check out the condition of the cam / tappets.

Chris.

kiwicar · Post by **kiwicar** » Tue Jul 14, 2009 12:56 pm

Have you got 20/50 in the sump? just often it is thinner oil that causes tappet rattle.
the other thought is thst using second hand lifters no a new cam will cause highly accellerated ware of the cam lobe. you either install both new at the same time or keep lifters matched to cam lobes.
Best regards
Mike

ian.stewart · Post by **ian.stewart** » Tue Jul 14, 2009 2:22 pm

I would have a 99% guess the cam is dead, Used cam used lifters, were they the same lifters used with the same cam, and were they fitted to the same respective lobes, and did you uses a decent break/anti scuff lube when refitting it all back together??

mgbv8 · Post by **mgbv8** » Tue Jul 14, 2009 4:35 pm

Could it be oil thinning as it gets hot and oil pressure dropping as well.
What is the hot oil pressure?

MAZVER · Post by **MAZVER** » Tue Jul 14, 2009 10:12 pm

The lifters are not paired with the cam in terms of wear. Am unaware of the condition of both of them really, in an ideal world i suppose it would be the best to replace them both however its not the cheapest so hoping to do a temporary fix i guess. Can get new lifters cheap as get cost price through a franchise here in NZ. Have used a 20w50 oil and is as clean as a whistle, however the noise does seem paired with oil thinning as engine heats up.... Oil pressure when hot at low rpm is strong, i think around 30psi
Thanks for your replys

RoverP6B · Post by **RoverP6B** » Wed Jul 15, 2009 2:50 am

MAZVER wrote,..

The lifters are not paired with the cam in terms of wear

Hello,

Well you have your answer then. Both the camshaft and the lifters will require replacing, and both camshaft and lifters MUST be new.

Where the camshaft and lifters are concerned, there is NEVER a cheap option.

Ron.

MAZVER · Post by **MAZVER** » Wed Jul 15, 2009 6:47 am

Ok fair enough, unfortunatly not within the budget at the moment!!

Any ideas on oil out the breathers? Took for a decent drive last night and it still seems to be doing it....

ChrisJC · Post by **ChrisJC** » Wed Jul 15, 2009 7:07 am

Is the crankcase ventilation system set up properly?

Chris.

MAZVER · Post by **MAZVER** » Wed Jul 15, 2009 8:57 am

Breathers all run into a oil catch cylinder that has a breather filter(Two rocker covers and crankcase breather).

Have inspected rocker shafts and rockers and they appear to be f*&%ed. So unfortunatly they are going to be the first things that need replacing. Possibly be a struggle finding a good second hand pair and a fortune for a new set!!! Are they interchangable between all the rover v8 engines?

ChrisJC · Post by **ChrisJC** » Wed Jul 15, 2009 9:00 am

In my limited experience, it's quite hard to define 'excess breathing'.

When I have had crank ventilation systems like yours, I always had 'engine smells'.

More recently I've got them connected to the inlet system so all the fumes get burnt. I get smoke on startup, but I can live with that.

I guess you need to check piston sealing and valve guides / valve guide oil seals if fitted. If not fitted, maybe change the valve guides for the most recent type, get the seats recut and fit the neoprene seals.

Chris.

MAZVER · Post by **MAZVER** » Wed Jul 15, 2009 9:05 am

I suppose if the shafts and rockers are worn excessively this may cause "oil flooding" in the top of the heads and may force oil down valve stem seals. I guess would be a combination of worn seals and too much oil maybe...

Cheers for you help

mgbv8 · Post by **mgbv8** » Wed Jul 15, 2009 12:14 pm

If the rockers and shafts are worn enought to flood the head i would have thought you would have very very low oil pressure.