Thread: Why doesn't the TD5 have a support arm on the manifold?

It depends on the cause of why the studs are snapping. You are assuming that it is the manifold, turbo and exhaust weight, but there is a common thread of thought that it is actually the heat warping the manifold that causes the brocken studs.

My old man was telling me the other day that some of the Audi's in South Africa with 5 cylinder motors also used to suffer from warped exhaust manifolds - perhaps it's a 5 cylinder thing?

Originally Posted by twr7cx

It depends on the cause of why the studs are snapping. You are assuming that it is the manifold, turbo and exhaust weight, but there is a common thread of thought that it is actually the heat warping the manifold that causes the brocken studs.

My old man was telling me the other day that some of the Audi's in South Africa with 5 cylinder motors also used to suffer from warped exhaust manifolds - perhaps it's a 5 cylinder thing?

I think it's a combo of the weight and heat. Even when temps are closely monitored to make sure they don't get too high, the studs still break (ie like mine have ). I have a madman and make sure the heat doesn't get anywhere near 700c and the top studs (front or back) are the ones that seem to snap.

A little analysis tends to show that the weight is a minor issue. Because the ends studs break it would suggest that it is combination of the type of metal used in the manifold casting, allowing considerable expansion under heat conditions, and typical manufacturing cost savings of using the smallest cheapest studs that will (usually) do the job.
A small change in either of these conditions such as the next stud size, or a metal recipe change in the casting might have stopped all this, but would have cost land rover heaps of money over the manufacturing lifetime of the td5.

That's why we have an aftermarket industry, because manufacturers produce something that works, then cheapen it down to save overall costs and maximise profits. Along comes the buyer and generally all is ok, but then the small, and sometimes larger issues appear and it's up to the aftermarket industry to help out....no cost to landrover, the aftermarket industry makes money, and we pay thru the nose, again, and again......
Let's face it, if the d2 was made the way we think it should have been, none of us would need to modify them would we?

Cheers
Kev

Originally Posted by gusthedog

I think it's a combo of the weight and heat.

What do you think the setup weighs? 25kg at most for the manifold, turbo and front exhaust pipe?

There are 10 studs or bolts holding this onto the side of the block. I can't recall there size but at a guess I'd say they're at least M6. 25kg for 10 M6 bolts is not much weight at all...

Originally Posted by twr7cx

What do you think the setup weighs? 25kg at most for the manifold, turbo and front exhaust pipe?

There are 10 studs or bolts holding this onto the side of the block. I can't recall there size but at a guess I'd say they're at least M6. 25kg for 10 M6 bolts is not much weight at all...

If we assume 25kg for the turbo, manifold, exhaust its important to remember that the weight is not directly pulling down or out on the m6 bolts. There are a number of pieces to the manifold, turbo and exhaust that place the weight out and down, kind of like a lever on the studs. Its not a straight pull. I think that this combined with vibrations, heat, weight and poor metalurgy cause the studs to snap. By supporting some of the weight with a support bracket it may help to aleviate the problem

If the support bracket doesn't work, why do other manufactures use one for their turbos/exhausts?

When mine broke for the second time I pulled out the 6mm studs and I then drilled, tapped and inserted 8mm studs. I also opened out the manifold holes slightly larger than necessary. Since then no more problems. Touch wood!!

Tony

Originally Posted by Grumpy

When mine broke for the second time I pulled out the 6mm studs and I then drilled, tapped and inserted 8mm studs. I also opened out the manifold holes slightly larger than necessary. Since then no more problems. Touch wood!!

Tony

Hopefully that sorts it for you Tony. I've kept mine standard m6 at the moment. I have heard that even uprated studs can snap. That's why I'm trying to think outside the box with a turbo/exhaust bracket. Might get something made up and report back if it works.

On my TD5,s Discovery and defender 130 removed the webbing on the manifold, have 300,000km on Discovery and have had no problems.