Engine noise - any suggestions?

[rpaterson]

Hi Folks,

I've cross-posted this on toher forums so some of you mayhave already read, and cintributed to this.

OK Folks, this is the continuining saga of my rattle. Under load, I'm getting a tappet-like rattle. It ONLY happens under load, I could red-line the engine in neutral and all would sound fine. Here's what the noise definately is NOT;

VIS - have swapped out a gutted manifold and the noise remains.
Alternator/power steering pump - have removed drive belt and the noise remains.
Purge valve - have unplugged it and the noise remains.

It's not a knocking noise, it's a tappety/fluttery/mechanically kind of 'Tttrrrrrr' noise. It's made the nosie since I bought it back in March 2009 so I'm fairly convinced that it's not pinking as my engine would be a pile of scrap by now if that was the case. I've also briefly unplugged the knock sensors to see if taking them out of the equation made any difference. It didn't.

It's had a few oil changes, most recently flushing it with Forte. No change. I've removed all of the tappets, cleaned them/freed them up and reassembled. No change. Also, wouldn't tappets be noisy all the time? I removed the tappets when I was changng the belts and I changed everything apart from the tensioner as I was supplied a duff part and I've not had a chance to re-do it yet.

Feels fine with regards to general performance and I consistently get 29-31mpg average over a tank. How do 'serious' noises like worn big ends etc manifest themselves? Are they more of a solid knocking noise? I see that there are youtube links on the forum to various noises, but I've got practically no 'net access in the house and youtube is blocked at work.

Any suggestions would be appreciated.

[man of kent]

If its done a load of miles, possibly low oil pressure related? Could be tappets not getting enough oil or the wrong viscosity. Cannot be bearings if you have had it from 2009. Tappets can do "funny things" re oil viscosity. They rattle so you put thicker oil in but no better. But, if you put thinner oil in which does not sound logical, the noise stops.

Could it be transmission related? Only happens under load and thus moving.

I note you said freed them up! If they were gummed up due to no oil changes you could have an oil flow problem.

Others may comment on this as I do not know the engine. Some engines have a non return valve in the block to stop oil running back from the top end. Possibly gummed up?. I had this on a Rover 2600 and not enough oil was getting to the top end. Does the top end look clean when you take the oil filler off? If its black its not had frequent oil changes.

[rpaterson]

Thanks for the pointers. It's had at least five, possibly six oil changes since I bought it. When I was working on the tappets, there was plenty of oil pooling around the cam carriers so I don't think that it's a supply problem. The oil was quite black, but it was due a change.

The tappets were a bit 'weird' in as much as upon removal, 20 of them were actually solid and I had to actually work them in a vice using a small socket to free them up. I wasn't able to strip these ones down to give them a total clean but they got cycled numerous times, flushed out with brake cleaner and flushed out with clean engine oil. With regards to the four that I was able to strip down, I was able to bottom them out once they were re-assembled so I wasn't sure if I'd overdone the cleaning on them? I didn't mix any of the parts up so I'm happy that this isn't the issue. To be honest, I'm still suspecting the tappets due to the 20 that I couldn't strip. I need to change the cam seals at some piont so I may as well pull the tappets out and either have another go at cleaning them or replace all of them (likely cost of 24 tappets - £120 ).

Transmission noise is an interesting possibility. I think I'm just blinkered on it being the tappets as that's the only thing I can think of that sounds like what I'm hearing.

[bl52krz]

How about the inlet manifold?

[MGMalc]

Originally Posted by GadgetBoy

Two things.

1. Fuel purge valve. Just behind the throttle body.

2. Classic KV6 fault. The power VIS butterflies.

Originally Posted by bl52krz

How about the inlet manifold?

Originally Posted by rpaterson

Here's what the noise definately is NOT;

VIS - have swapped out a gutted manifold and the noise remains.
Alternator/power steering pump - have removed drive belt and the noise remains.
Purge valve - have unplugged it and the noise remains.

As above, what the OP stated.
Could it be the tensioner, which you didn't replace?

[tsautos]

Cambelt idlers ?

[dissy1810]

Originally Posted by rpaterson

Thanks for the pointers. It's had at least five, possibly six oil changes since I bought it. When I was working on the tappets, there was plenty of oil pooling around the cam carriers so I don't think that it's a supply problem. The oil was quite black, but it was due a change.

The tappets were a bit 'weird' in as much as upon removal, 20 of them were actually solid and I had to actually work them in a vice using a small socket to free them up. I wasn't able to strip these ones down to give them a total clean but they got cycled numerous times, flushed out with brake cleaner and flushed out with clean engine oil. With regards to the four that I was able to strip down, I was able to bottom them out once they were re-assembled so I wasn't sure if I'd overdone the cleaning on them? I didn't mix any of the parts up so I'm happy that this isn't the issue. To be honest, I'm still suspecting the tappets due to the 20 that I couldn't strip. I need to change the cam seals at some piont so I may as well pull the tappets out and either have another go at cleaning them or replace all of them (likely cost of 24 tappets - £120 ).

Transmission noise is an interesting possibility. I think I'm just blinkered on it being the tappets as that's the only thing I can think of that sounds like what I'm hearing.

i would guess the 4 hydraulic followers you could move are the ones at fault the others sound like they are holding pressure and not leaking where as the 4 you could move were not

[rpaterson]

I'm definately suspicious about the tappets. My confusion comes from people telling me that if a tappet is on the bench and is dry then I SHOULD be able to bottom it out with finger pressure. Come back screw-and-locknut, all is forgiven! When I say that the others were solid, then I mean SOLID. A tappet shouldn't be that resistant to moving should it? Plus if they were that rigid then surely they'd be holding valves open???

I'll get around to swapping out the tensioner when I get around to changing the cam seals sometime this year. I'll either replace the tappets at that time or have another go at cleaning them. Annoyingly if this sures the noise then I won't be able to pinpoint what it was as I'll have changed both of the suspects! Tempting to just do the tappets and then re-assemble it all for a test drive, but that doubles the length of the job as I'll need to strip it back down again to a degree in order to change the tensioner

[Trophy Blue Tourer]

Originally Posted by rpaterson

I'm definately suspicious about the tappets. My confusion comes from people telling me that if a tappet is on the bench and is dry then I SHOULD be able to bottom it out with finger pressure. Come back screw-and-locknut, all is forgiven! When I say that the others were solid, then I mean SOLID. A tappet shouldn't be that resistant to moving should it? Plus if they were that rigid then surely they'd be holding valves open???

I'll get around to swapping out the tensioner when I get around to changing the cam seals sometime this year. I'll either replace the tappets at that time or have another go at cleaning them. Annoyingly if this sures the noise then I won't be able to pinpoint what it was as I'll have changed both of the suspects! Tempting to just do the tappets and then re-assemble it all for a test drive, but that doubles the length of the job as I'll need to strip it back down again to a degree in order to change the tensioner

The 20 tappets you couldnt strip or compress may be 'sluged up' to the point the oil being fed to them cant enter and expand them thus they are running with to much clearance to the valves so giving you your problem!!

I had this problem on a VW golf many years ago and as the owner had little cash for the repair we put a tin of "forte" engine flush into it and put it out side the workshop to tick over (fast about 1400 rpm by adjusting the throttle cable!!) for a bit !! the noise was causing all of us to twich by the time something happened about 90 mins later!! the noise just faded away!! lovely!! took about 90/120 seconds to go quiet as first one then another freed off!! by the time it had finished going silent all 5 of us were standing by it grinning with our hands on our hips!! wizzed it in to the work shop did the oil and filter refilled it and started it !! it just purred!!

The owner had brought the car to us after the main agent had told him how much it was going to cost!! - he couldnt really afford for us to do it either even though we charged about 1/2 the amount per hour VW did so I offered to try the flush "cure" for the price of an oil and filter change with the flush also of course! - 30 mins labour + oil flush + oil and filter made him a very happy bunny at 5-30 and gained us a customer for the next 5 years untill he moved away!! + loads of recomends he sent round!!

Just a thought!! might be worth a try!! - I personally ALWAYS use a flush when doing an oil/filter change these days partly due to the above experiance!!

If you still have them out of the car?? immerse the tappets in some paint thinners/carb cleaner or the like overnight before you try and strip them!!

If you have had 4 of them apart then you know how to get the rest apart!! if you have to get a bit heavy handed thats ok as long as you can strip and clean them eventually!! lets face it!! if you cant strip them or you damage them trying then you need to replace them anyway!! - you can - not that I would recomend it of course!! - just replace as many as you cant strip/clean if moneys a bit tight!!!

HTH??

Andy

[COLVERT]

Originally Posted by rpaterson

Hi Folks,

I've cross-posted this on toher forums so some of you mayhave already read, and cintributed to this.

OK Folks, this is the continuining saga of my rattle. Under load, I'm getting a tappet-like rattle. It ONLY happens under load, I could red-line the engine in neutral and all would sound fine. Here's what the noise definately is NOT;

VIS - have swapped out a gutted manifold and the noise remains.
Alternator/power steering pump - have removed drive belt and the noise remains.
Purge valve - have unplugged it and the noise remains.

It's not a knocking noise, it's a tappety/fluttery/mechanically kind of 'Tttrrrrrr' noise. It's made the nosie since I bought it back in March 2009 so I'm fairly convinced that it's not pinking as my engine would be a pile of scrap by now if that was the case. I've also briefly unplugged the knock sensors to see if taking them out of the equation made any difference. It didn't.

It's had a few oil changes, most recently flushing it with Forte. No change. I've removed all of the tappets, cleaned them/freed them up and reassembled. No change. Also, wouldn't tappets be noisy all the time? I removed the tappets when I was changng the belts and I changed everything apart from the tensioner as I was supplied a duff part and I've not had a chance to re-do it yet.

Feels fine with regards to general performance and I consistently get 29-31mpg average over a tank. How do 'serious' noises like worn big ends etc manifest themselves? Are they more of a solid knocking noise? I see that there are youtube links on the forum to various noises, but I've got practically no 'net access in the house and youtube is blocked at work.

Any suggestions would be appreciated.

Big ends. Fast medium note noise. Increases with revs.
Main bearing deeper more solid clunk. From the crankcase area.
Piston slap. Higher pitched sort of rattle under load. From middle of engine.





Colvert.