Strange noise from inlet manifold

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Shifty1962

Shifty1962

Well-Known Member
Posts
4,209
Location
The Winchester Club - Englandshire
Right I've spent over an hour searching but no joy so here goes ......

Driving home tonight I thought I heard a strange sound from the engine bay. Whilst walking around the car in the ****ing rain it became apparent it was coming from the air inlet grill in the right wing.

The noise is like a regular thumping in time with engine speed. I initially thought of big/small ends but on taking off the intercooler to inlet manifold pipe the now very loud noise was just like running an engine with no exhaust box BUT COMING FROM THE INLET MANIFOLD ???.

It increased with engine revs. The engine is not down on power and runs sweetly but this noise is new and very worrying.

Anybody got any ideas? My thought was that I had a sticking inlet valve but there is no apparent back pressure in the inlet manifold and the engine is running on all five with no problems and starts up as normal. The only thing I can think of is if the head has failed between an inlet and exhaust valve but I'm not sure that this is even possible.

I dont want to cause any further damage by driving the motor but I need to sort it for my work.

Help .........
 
don't suppose you've had a GOOD look at the manifold ? - they are prone to develop hairline cracks, if the cast webbing is removed it allows it to flex slightly and helps prevents is cracking again
 
I had a similar noise from the exhaust manifold. Found what it was when I took the manifolds off to clean them out when I removed the EGR valve. The manifold stud closest to bulkhead had come out, and blown the gasket.

Easy fix, hope yours is too .. :)
 
I'd suggest that you whip the rocker cover off and check the tappet adjustment on the drivers side of each rocker arm. I repaired a 300TDi with the same symptoms last year. The ball that sits in the top of the push rod cup had sheared off the threaded adjuster on the rocker arm so that the exhaust valve on no. 3 cylinder was not opening. Definitely worth checking. Is it a hard smacking metalic sound?

-Pos
 
pos said:
I'd suggest that you whip the rocker cover off and check the tappet adjustment on the drivers side of each rocker arm. I repaired a 300TDi with the same symptoms last year. The ball that sits in the top of the push rod cup had sheared off the threaded adjuster on the rocker arm so that the exhaust valve on no. 3 cylinder was not opening. Definitely worth checking. Is it a hard smacking metalic sound?

-Pos
Click to expand...
The manifold is not cracked .

Yep it is a hard metalic sound - especially with the turbo pipe disconnected from the manifold. The TD5 has hydraulic tappet adjusters so there is no adjuster as such but I guess it could be a problem with one of the rocker arms.

I'll get the lid off and have a look to see if its anything obvious. Fingers crossed its a simple fix as I cant afford another new cylinder head. Anybody know of a TD5 engine for sale just in case ?
 
Right after some investigation this is the situation.

Took the top off and nothing is obviously broken. All valve followers and injector rockers are tip top and properly adjusted.

Put the lid back on and ran the engine then I noticed some puffing from the cam cover breather which never used to happen. Took the dipstick out and blocked the breather and got puffing from the dipstick tube. Blocked the dipstick tube for a few seconds and got a face full of oil when I took my thumb off it. Therefore the crankcase is pressurising even at idle.

This now looks like a piston or rings problem. Bugger. I'm thinking rings because the engine idles lovely and does not seem down on power. There is no audible piston slap (using a steel rod as a listening device) which is a good sign. In which case I'm hoping it should be a relatively cheap fix.

I'm thinking honing then new rings on all pistons etc. Anybody tried one of them honing devices that you can use with the block in place? You drop the bottom out and use a drill to power the stones. Otherwise if I have to take the block off I may as well do a complete rebuild and clutch etc.

Can anyone confirm I'm on the right track before I tear the engine down?
 
Started removing stuff to get a better look.
Inlet manifold off and full of black ****e. Its not comming from the breather via the interccoler though as the hoses are pristine so it must be blowing back through a head valve somehow.
Started the engine with no inlet manifold and the noise is coming from the number one cylinder port (front of engine) but there is no obvious back draft. Crankcase is still pressuring though so I reckon I'm in a for a full rebuild as a cylinder head fault alone could not cause the pressurisation.
Spoke to a bloke over near Heathrow who says you can get oversize pistons for the TD5 and it is possible to rebore. He even has a complete bottom end ready to go and wants £800 for it. Also says if my block is servicable he would rebore, hone, fit new pistons and rings, new bearing shells, main bearings all for the same money. Does everything on site and has no problem with me looking round the factory and watching him do the work.
I'd still need to get a cylinder head though so I reckon I'm looking at a bill around the £2.5k mark if I pull the engine myself.
 
Ouch, sorry to hear of your troubles Shifty.


Could this have anything to do with running on the waste oil/diesel mix?
 
I didn't realise is was a TD5 sorry! Bloody hell that's a load of time, effort and expense that you don't really need. It's very typical of the TD5 though. They're fantastic engines when they're working, but when they do go wrong, it's a very expensive ordeal to sort out. £800 for a full bottom end rebuild is quite reasonable but it's still a hell of a lot of money either way. If you do decide to go about it yourself DO NOT assume that a glaze busting tool that you stick on the end of a drill is anything special, and it most certainly will not hone your bores. They're designed purely to remove the glaze in the bores if your'e just fitting new rings, so that they can bed in properly and you only need to run it up and down each bore about ten to fifteen times with some 'honing oil' being sprayed in at the same time. You will need to fit standard sized pistons and rings in this case. If you do get it honed out (which an engine of that age shouldn't really need), it needs to be done on a cylinder honing machine at a workshop somewhere that will cut each bore accurately. The cylinders will then require oversized pistons and rings. I'd be tempted to let him do it for you, but then again that 800 quid could go nicely towards a new cylinder head. Why do you actually need a new head out of interest? I thought you didn't find any faults?

-Pos
 
I dont reckon its got anything to do with running on home brew as this is a mechanical failure. The engine was running sweet as before this and was spot on the money for power and torque. It does not get thrashed but it has done 120k miles. It never burnt any oil but when I first got it I had the diesel in the engine oil saga and I dont know how long the previous owner had been driving around like that. I found out when the turbo let go. I took a chance and picked up a used head for £400 which is what is on there now.

Until I get the head off I dont know that I need one but I'm expecting the worst so that I may be surprised when I remove it. The black crap in the inlet port could only get there by blowing back past the inlet valve or if there is a crack between the inlet and outlet ports in the head. Hopefully it will be a dodgy valve which I can sort out relatively cheaply. The crankcase pressurisation is the worrying thing though which is why I will need a bottom end rebuild. I'll know more next week when I tear into it but for now I'm going down the pub with my old lady to drown our sorrows.

Other alternative is to pick up a complete used lump and just switch them. Rebuild the old one and sell it on to help pay for things.
 
Should have took my £800 when I offered it to you. :p

Sorry, sorry to hear about the bad luck you are having though. I know how it feels believe me (bloody LPG:mad:)
 
Have you ever thought of taking a slightly different route and fitting a different engine altogether? If you remove and rebuild your TD5 (and do it well in your free time), you should be able to sell it for anything between £500-£600. You could then source a different engine such as a cummins 6BT or an Isuzu / Iveco for example and fit that. It sounds like you've had trouble with TD5's in the past (which isn't surprising). You should be able to 'drop' one in for less than you can sell the TD5, including all the parts that you'll need. I'd definitely consider it. That way you know that you're getting a reliable engine that isn't known for head failures or anything similar and it'll be like having a whole new landy with similar performance. Even a 200TDi or a 300TDi would make a nice backwards upgrade if you think about it. I've seen one brand new Perkins diesel engine go for a few hundred quid on ebay about two months ago. Some folks even put Detroits on ebay - they'll pack some punch and they sound great but they'll need more work when it comes down to fitting etc.

-Pos
 
Okey dokey.
Took the head off and this is what I found so far.

All pistons look good with little or no carbon. Light buff colour so my homebrew mix is not causing any problems.
Bores look excellent with original honing still even and visible on all pots. No nasty wear marks or scratches that should not be there. Not checked rings yet but thats a pistons out job for another day.
Cylinder head gasket all good with no signs of blow by.
Camshaft showing excessive wear which was not there 2000 miles ago. Lobes are deeply pitted and some signs of metal dragging on a few of them. May be the source of the metallic noises I was hearing through the inlet manifold???
Hydraulic followers all seem clean and in good shape.
Injector shaft rocker rollers are all shot to bits. Deep scores and definite signs of overheating (blueing) as are the injector shaft cam lobes. This suggest lack/loss of oil to these components which is strange as I have an oil pressure gauge and the oil light never came on after startup. Maybe the drain back valve in the camshaft oil feed was not working so everytime I started the engine the top half ran dry for a few seconds???
I reckon the motor has been on borrowed time for a while and can only guess the crankcase pressurisation is due to knackered rings after 120k miles.
I'm going to get the bottom end re-honed and fit new rings if the crank and bearings are all reasonable. If not I'll go for the £800 rebuild from the guy at Heathrow. New oil pump and a Turners' head should sort it out. Must remember to locktite the oil pump sproket bolt.Turbo is pristine with no signs of impellor vanes touching the casing which also suggests that oil delivery was not an issue.

Still looking at the thick end of £2500 though but I'll have a motor that will be good for another 100k + miles.

Pictures of the strip down to follow.
 
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