Crankshaft tight rotation

jacckk · Post by **jacckk** » Sat Apr 19, 2014 9:51 pm

The lifters from the old engine are only about 2000 miles old. Is there any way to test they are working properly?

jacckk · Post by **jacckk** » Sun Apr 20, 2014 8:06 pm

I took the intake manifold off today and found that one of the lifters can be pushed down very slightly. All of the other lifters are solid and can't be moved at all. Does that sound like the cause of my problem?

Can I buy a new set of lifters and use them with my current cam? I know ideally you should replace them together but the cam and lifters have only covered 2000 miles. If so should I buy a new set or just one lifter?

ChrisJC · Post by **ChrisJC** » Sun Apr 20, 2014 8:31 pm

In my experience, once pumped up, the lifters are as good as solid. So it does sound like one of them is duff.

Chris.

DEVONMAN · Post by **DEVONMAN** » Mon Apr 21, 2014 9:03 am

Given that you have already got the manifold off, I would take out the duff lifter and take it apart for inspection. The fault may be obvious, a bit of crud or something.
I have in the past fitted new internals to an old lifter shell to keep the matching shell and cam lobe together. But, you probably would need to find a new lifter from the same manufacturer.

Denis

jacckk · Post by **jacckk** » Fri Apr 25, 2014 1:45 pm

I got a new lifter and put the new internals into the old shell. I've put that in the car and there's still no difference. All of the other lifters didn't have any slack in them so I didn't replace them.

I've noticed that the noise is quieter on overrun. When accelerating the noise is the loudest and cruising and overrun are both fairly quiet. Does that still sound like a lifter or would that make a the same amount of noise when both accelerating and cruising?

It still definitely sounds like it's coming from th centre of the V rather than at the side from the exhaust manifolds.

DEVONMAN · Post by **DEVONMAN** » Sat Apr 26, 2014 4:51 pm

If a noise is load related it's not normally a camshaft problem.
I can only suggest that you momentarily pull each spark lead in turn and see if the noise changes. This should tell you which cylinder has the problem.
It seems a slow noise (ie half engine speed/camshaft speed) but the noise may be apparent only on the firing stroke.

jacckk · Post by **jacckk** » Mon Apr 28, 2014 7:33 pm

I got a video of the noise whilst driving it to show the difference between accelerating and not.

https://www.youtube.com/watch?v=ZvIHdF7wLYA (You might need to turn it up to hear the noise)

I haven't took each lead of whilst it's running but I did do a compression test and the lowest was 130 and the highest 145.

DEVONMAN · Post by **DEVONMAN** » Mon Apr 28, 2014 7:54 pm

jacckk wrote:I got a video of the noise whilst driving it to show the difference between accelerating and not.

https://www.youtube.com/watch?v=ZvIHdF7wLYA (You might need to turn it up to hear the noise)

I haven't took each lead of whilst it's running but I did do a compression test and the lowest was 130 and the highest 145.

Sorry but I can't hear much from the video.
Did u check that with the modified lifter fitted, the push rod feels ok and cannot be pushed down like before.

Based on the first video, I'd say it's a cam/lifter related noise.

jacckk · Post by **jacckk** » Mon Apr 28, 2014 8:30 pm

Yeah it's quite quiet. I can hear it on my laptop with the volume on full, its kind of a rasping sound in the background.

The one that I replaced couldn't be pushed down. I watched it with the engine running and there's no noise coming from the drivers side bank of rockers whilst running.

mgbv8 · Post by **mgbv8** » Mon Apr 28, 2014 9:57 pm

I can hear a rattle on the video. !!

jacckk · Post by **jacckk** » Tue Apr 29, 2014 9:21 am

I'm thinking of just replacing all the followers with new ones. At least then I'll know none of them are broken.

How likely am I to wreck my cam doing that, would I be ok since it's fairly new?

stevieturbo · Post by **stevieturbo** » Tue Apr 29, 2014 10:26 am

jacckk wrote:I'm thinking of just replacing all the followers with new ones. At least then I'll know none of them are broken.

How likely am I to wreck my cam doing that, would I be ok since it's fairly new?

Replacing with new followers should be fine.

jacckk · Post by **jacckk** » Thu May 01, 2014 9:11 pm

New followers and pushrods haven't cured it

stevieturbo · Post by **stevieturbo** » Thu May 01, 2014 9:17 pm

Noise is exactly the same ?

Try removing an injector plug 1 cylinder at a time, see if the noise changes. That may help identify a particular cylinder.

A slightly more awkward test, remove the pushrods from a cylinder at a time and run the engine, again to see if this pinpoints which cylinder is making the noise

jacckk · Post by **jacckk** » Thu May 01, 2014 9:30 pm

Ok thanks, I'll try that tomorrow if I get time.