Squeaky engine noise

vanquishspirit · Post by **vanquishspirit** » Sat Jan 12, 2008 7:20 pm

Can anyone help please? I have just run my newly rebuilt 3.5 V8 engine. It has a rather concerning irregular squeak. Now when I investigated it I realised I had incorrectly assembled the new rocker shafts thereby starving the rockers of oi and hence the pushrod tops. Anyway having rectified this I restarted the engine and it is much better but still there is this worrying squeak. I have isolated the water pump and alternator, they are not at fault. So my question is what is it?. Could it be the camshaft, possiblly the end float, the distributor or anything else. This engine is a very early example with the old graphite front oil seal. I replaced this with an o ring. I have also upgraded the oil pump with an RPI ket, spacer and bigger gears. Could this squeak if the end float is incorrect? Anyway any ideas?

mgbv8 · Post by **mgbv8** » Sat Jan 12, 2008 8:29 pm

I fitted the hi flow pump kit to my 3500. And the resistance at high rpm with 20/50 oil was enough to shred 3 cam cogs in as many months while sprinting it.
Can you not pinpoint the location of the squeak? Try a stethoscope or screw driver to the ear around the engine to see if you can at least get a rough location.

RoverP6B · Post by **RoverP6B** » Sun Jan 13, 2008 3:56 am

Did you fit complete new rocker assemblies,..ie shafts, rockers etc after you found that the original installation was incorrect and they had been starved of oil?

The rocker assemblies, if the same ones, only now correctly installed, may have been damaged, and as such should be replaced in their intirety.

Warn contact points between the pushrods and the rockers will typically squeak when they are worn and the steel inserts within the aluminium alloy rockers are at the point of failure.

Are you using 20w50 engine oil? What is the oil pressure like at idle, engine hot at 85 degrees C or so?

jefferybond · Post by **jefferybond** » Sun Jan 13, 2008 11:58 am

Does the squeak go away when you raise the revs a bit?

If you fitted a new cam and lifters, it's probably these that are squeaking, and it's not good for it!

You need to run the motor at about 2000rpm for about 20 minutes after a cam/lifter change, so that the cam beds in properly.

Jeff

vanquishspirit · Post by **vanquishspirit** » Mon Jan 14, 2008 8:39 am

Hi Guys, lots of really good ideas here, let me try to answer all your questions now.

MGBV8.. i have tried to identify the location of the noise with a screw driver with no sucess as yet. I can only say that I did run the engine with the rockers off and it was much noisier. That could be the noise travelling up throught the pushrod holes from the cam or elsewhere though.

Rover P6B..I have not refitted new rocker shafts or rockers as the engine has only been run for a short time. I think it is fair to say that there was some oil making its way to the rocker shaft but not enough. You may have a point though. The shafts that i bought were from RPI and did not have any identifying grooves in the end. They were also plated in a slightly yellow colour that has worn throught to the steel silver colour in places where the rockers have been running. I did not mike up the shaft to check but it may be worth thinking about . The noise did not appear for about 10 mins after she was first started.

I fitted all new rockers but not new pushrods. The engine had been badly neglected before and whilst only having covered 48k miles I dont think it had ever had an oil change. The internals were the muckiest I have ever seen. The oil is 20/50w. I do not have an oil guage fitted although my chum who fitted the engine did at first and was happy it was correct. I can easily recheck if its important.

Jeffrey bond..yes the squeak goes when I run at higher revs. I did fit a new cam but not new cam bearings. Also fitted all new Cam followers/lifters.
If this is so will it settle down or is it a replacement cam again and is there anyway I can definitely isolate the problem? The worst of this is not knowing what to change. Grrr!

Bit disappointing as I put so much time and effort into this rebuild and the rest of the engine sounds superb. I have to sort it as a V8 sounds so superb when correct.

please let me know you thoughts, thankyou to you all.

Ian Anderson · Post by **Ian Anderson** » Mon Jan 14, 2008 8:51 am

How about something simple like squeaky engine mounts and the engine rocking accosionally?

IAn

jefferybond · Post by **jefferybond** » Mon Jan 14, 2008 10:01 am

vanquishspirit wrote: Jeffrey bond..yes the squeak goes when I run at higher revs. I did fit a new cam but not new cam bearings. Also fitted all new Cam followers/lifters.
If this is so will it settle down or is it a replacement cam again and is there anyway I can definitely isolate the problem? The worst of this is not knowing what to change. Grrr!

The reason I asked previously was because mine did this also. Exactly the same as your problems. Noisier when rocker covers removed, goes away at higher revs etc.

It's definitely the new cam and followers squeaking. With a bit of luck, you won't have done them any harm (mine survived OK!), but next time you start it you need to keep it at 2000-ish rpm for around 20 minutes if you can (noise and neighbours permitting!) This should finish the bedding in process and the squeak will gradually fade an disappear.

Jeff

vanquishspirit · Post by **vanquishspirit** » Mon Jan 14, 2008 10:35 am

Great , I feel better now. Actually have just spoken to a mate who rebuilt an MGBV8 engine years ago and he remembered what you said about 2000 rpm, although, none of the engine build books I read mentioned it. Anyway, have passed the info onto my pal who is rebuilding the rest of the vehicle for me and he is going to try it, hopefully today. So I will let you know asap.. Here's Hoping.

thx

vanquishspirit · Post by **vanquishspirit** » Mon Jan 14, 2008 10:36 am

oh and Ian, its not the engine mounts, its definitely an internal engine noise, you would agree if you could hear it. but thx anyway

vanquishspirit · Post by **vanquishspirit** » Mon Jan 14, 2008 10:05 pm

spoken to someone who tells me that , sure it is advisable at to run a new camshaft at 2000 rpm but only if its an old engine. This guy, who does rebuild these engines is confident that it is a rocker shaft/rocker/pushrod squeak. In his opinion, and hemay be wrong. One should not run a new engine at 2000 rpm because whilst it is ok for the camshft its not good for the main bearings or piston ringsetc. So there you have it. Thoughts?

jefferybond · Post by **jefferybond** » Tue Jan 15, 2008 8:33 am

vanquishspirit wrote:spoken to someone who tells me that , sure it is advisable at to run a new camshaft at 2000 rpm but only if its an old engine. This guy, who does rebuild these engines is confident that it is a rocker shaft/rocker/pushrod squeak. In his opinion, and hemay be wrong. One should not run a new engine at 2000 rpm because whilst it is ok for the camshft its not good for the main bearings or piston ringsetc. So there you have it. Thoughts?

Well, when I had my squeak, I initially suspected the rockers and rocker shaft (since they were old), so I replaced them for new items. This did not affect the squeak at all. It'll be the cam for sure! It will go away if you run it for a bit longer, just keep the revs high enough so the squeak stops if you don't fancy going to 2000rpm (which isn't fast!)

I don't believe the story about damaging the bearings or rings either. In fact, raised RPM might be better for them since the oil pressure will be higher. Actually i've heard stories that a bit of gentle load on the engine actually helps the rings bed in.

Jeff

vanquishspirit · Post by **vanquishspirit** » Tue Jan 15, 2008 8:51 am

Jeff, thanks for this. I sort of decided that the noise was slowly becoming less the more I ran the engine, so its does sound like you could be correct. Anyway, the good news is that nobody seems to think its anything terminal ! I will run the engine more and let you know. Thanks very much for the really useful feedback guys. Oh, and one last question. How often do you think the oil should be changed (20/50?). I am told they can sweat a lot due to the aluminium crankcase which congeals the oil and clogs the engine up more and more until the start to breath into the crankcase and the whole process accelerates?

jefferybond · Post by **jefferybond** » Tue Jan 15, 2008 9:19 am

Ive just uploaded a video of my first startup to youtube. It shows the squeak I had, and you can tell it gets worse as the revs drop. You can also tell that the noise is less at the end of the video. You can also see my dad oiling the rockers in a failed attempt to make the noise stop! After a few more runs it had gone away completely.

Yes, I know the starter was knackered and the ignition retarded!

Vid here:

http://www.youtube.com/watch?v=3VZ9aRJpW-4

Jeff[/url]

JSF55 · Post by **JSF55** » Tue Jan 15, 2008 9:30 am

Well i had a similar noise once on a essex v6, spent months chasing it, fine at revs, squeeked like a buggerat tickover ......... it was a mismatched sump and dipstick, the engine was about 2 pints short of oil all the time, so depending on how and who built the engine i'd give that area a check through, john

RoverP6B · Post by **RoverP6B** » Tue Jan 15, 2008 9:39 am

Vanquishedspirit,

For the first fill of 20w 50 oil after the rebuild, best not to leave the oil in for any longer than say 500 miles, changing the filter at the same time.

After that, change the oil and filter every 2000 to 2500 miles if possible. As an absolute maximum every 3000 miles.

My original 3.5 litre engine clocked up 203,000 miles (327,000km), with oil and filter changes as detailed above.

The only parts that were changed within the engine in that time were the rocker shafts and head gaskets.

After stripping down the engine completely after removal, the main and big end bearings were all displaying substantial areas of copper, the camshaft bearings only had some copper left on the upper 180 degrees, the lower 180 degrees displayed no copper at all, it was all worn away, with the camshaft journals running on the steel backing.

The original Morse type timing wheel with it's nylon teeth were all but worn away, only one tooth remained! A near potential disaster was almost in the making had the chain slipped!!

There was no sludge anywhere, the oil pump gears looked like new and the inside of the gear chamber within the timing cover was smooth and free of scoring. Oil pressure at idle prior to removal was typically 20 to 25 psi, and 35 psi at 3000rpm, coolant temp approx 78 degrees C.

Best of luck!
Ron.