Thread: Really nasty noise - 3.5 V8

Originally Posted by BigJon

After the 4wd trip yesterday my engine is making very bad noises.

On cold start there is a loud "grinding" noise, not a knock, which goes away when oil pressure builds (a couple of seconds).

If the engine revs are increased to about 2500, the noise returns.

An engine oil (20w 50) and filter change this morning lessened the noises, but certainly didn't cure them.

At this stage the plan is to pull the sump off tomorrow morning and have a peek at the big end bearings. I assume I can replace them (if need be) with the engine still in place.

Is it possible to replace the main bearings as well, or is there not enough room to slip them past the crank?

I don't want to chance the drive home as is, a breakdown could be very expensive with regards to towing charges.

Possibly main bearing noises Jon, Not big ends, as there is no knock just a grinding rumble.... BUT, check the harmonic balancer isn't delaminated, is there a possibility that it has been hit or damaged? I would disconnect all the belts too and eliminate all the ancilliaries from the equation.

You can slip the mains past the crank if they are all ondone at the time. The trans spigot and the timing chain will prevent damage to the front and rear seals by not allowing the crank to 'drop' too much. IF a mains has gone, the crank won't be too exciting but it will get you home. Same with the big ends, if they're worn just throw a set in and it'll get you home at least.
Bad luck Mate, Hope this isn't the problem

JC

Thanks JC,

Big ends weren't my first thought, as you say there isn't a knock.

Interestingly the noise occurs on gearchanges, but only very briefly. The noise sounds almost like a TD5 running under load, if that helps explain it at all.

I haven't looked very closely at the crank pulley yet, I will go outside now and look.

If you look here bigjohn_10-01-2009.flv - Video - Photobucket - Video and Image Hosting

there is a short vid of the near vertical drop off I went down early in the day. The Rangie was then stuck in the mud (engine running) for a couple of minutes until it was snatched out (no wading plug in ).

Crank pulley seems OK.

With all the belts removed the noise remains the same.

Nasty grinding rattle for a second or two until oil pressure comes up.

Originally Posted by BigJon

Crank pulley seems OK.

With all the belts removed the noise remains the same.

Nasty grinding rattle for a second or two until oil pressure comes up.

hmmmm, perhaps sump off and some pics tomorrow? Not a great way to spend a holiday

JC

Yes, you can replace the big-ends bearings in situ. I've done it on my old 4.6.

The hardest thing is torquing them up. Not sure about the 3.5 but the 4.6 specifies an angle. Without a Snap-On torque-angle wrench, it's a pig.

Originally Posted by justinc

hmmmm, perhaps sump off and some pics tomorrow? Not a great way to spend a holiday

JC

That is the plan at this stage. Who wants to go to Fraser Island anyway?

Originally Posted by p38arover

Yes, you can replace the big-ends bearings in situ. I've done it on my old 4.6.

The hardest thing is torquing them up. Not sure about the 3.5 but the 4.6 specifies an angle. Without a Snap-On torque-angle wrench, it's a pig.

30 to 35Nm for the 3.5/ 3.9 Big end nuts, and I think 90 to 105 Nm for the Main caps. I'll have to refresh my memory and repost up tomorrow.

JC

Originally Posted by p38arover

Yes, you can replace the big-ends bearings in situ. I've done it on my old 4.6.

The hardest thing is torquing them up. Not sure about the 3.5 but the 4.6 specifies an angle. Without a Snap-On torque-angle wrench, it's a pig.

I have found the following

Tuning the Rover V8

Hopefully those torque settings are accurate.