Thread: TD5 Exhaust manifold failure

I think it has to do with different expansion rates between the head and the manifold. The manifold is a very stiff design, and as it expands the outer studs where the majority of the movement and so fail first. I think the stiff design also has a lot to do with the warping of the manifold.

The other thing which would be interesting to know, is what you were doing to warp the manifolds.

I'm chipped and intercooled MY00.5 and have done 2 manifolds.

The first one was driving around the Cape at speed with and overloaded jalopy, roofrack, 34" Simex at 20psi on dirt corrugations. The constant load for 3 weeks did it.

The second one was in the NT driving at 163km/h while loaded. This was running with a bigger ECU upgrade than normal and a blown MAF fuse. This one also went with upgraded 10mm studs. I'm actually surprised it doesn't cause more head failures, or perhaps forced movement from the manifold is causing problems like moving heads and blown gaskets but nobody has yet related them.

I would bet that Disco's that do a lot of towing (hence high EGT's) will also be the most prone to warping the manifold, of course apart from those that are chipped.

had two disco td5s both did 90000ks no manifold probs.latest one done 65000&no exh. manifold problems either. none were chipped& dont do any towing.
they all did hard 4wding particularly in sand.

i was either lucky or they didnt have enough miles on them,or they were not worked hard enough

what does the egr do? is it only for emissions or does it help to warm the engine up?if it was playing up would it cause high egtemps?

cheers

EGR is the Exhaust Gas Recirculation.

what it does is put exhaust gasses in the inlet manifold so that the combustion temperature is lowered and there is less free O2 in the intake charge to get converted to oxides of nitrogen during the combustion process when running lightly throttled.

00my, no mods or chips, average 4wding, rear studs went at 100k just after i bought it.

Upgraded ecu & I/C 55K kms ago - now 159K kms and no problems (yet?).
The engine gets an easy life mostly. EGR has only ever been operational on warranty service days.

Guys...

Take a little look-see here:

TD5 Manifold Fix

Hopefully this will help those in the future.

Originally Posted by Tombie2

Guys...

Take a little look-see here:

TD5 Manifold Fix

Hopefully this will help those in the future.

Hey thats cool. I'll have to do one of those with the full grind next time I warp a manifold. I'm not decided about slotted holes though. I'm not sure it's good to have the bolts that loose or to have the manifold sliding under tension like that, but getting the flex happen in the manifold! Yeah! Loved the stainless job, thats cool!

Originally Posted by Slunnie

Hey thats cool. I'll have to do one of those with the full grind next time I warp a manifold. I'm not decided about slotted holes though. I'm not sure it's good to have the bolts that loose or to have the manifold sliding under tension like that, but getting the flex happen in the manifold! Yeah! Loved the stainless job, thats cool!

I didnt slot the holes...

I did the Ceramic coating and instead of going the 'full grind' I just used a 3mm grinding disc to slit each of the webs down to the manifold itself.