worried about exhaust gas temp at manifold collector.

[90gst_sean]

I have a rebuilt engine with a 20,000 mile evo turbo. I've had problems with my exhaust heat shield bolt for the top piece trashing the little bolt that holds the shield to the collector part of the mani. I didn't think much of it though and just used a new bolt every time I needed to remove that shield; due to the manifolds old age..

But this time I removed the lower shield to check my gate actuator arm travel and had the same problem right there are the face of the turbo just under the other problem bolt. After braking the bolt lose, it backs out a turn then binds. I can remove the bolts fine with some work, but the threads are eaten at the end and its getting old. It worries me because I dont have this problem with any of the other bolt holes for the shields and the turbo/bolts are pretty new so I dont think its from bad threads in the turbo. There must be more to it.

Could I be running hot, causing the bolts to over heat? Could I be inches from a melt down and not know it? Or is this common?

This last bolt was in great shape 3000 mile ago, when I installed every thing after my rebuild.

NOTE: My Walbro 255 is a new install of 50 miles.

On a side note. Can I run with out the bottom shield. I dont think I'd remove the top one but the lower shield seems in a better spot to leave off.

 

[GVR4592]

It sounds like the threads are damaged in the manifold and eating up the bolt during installation. Run a tap with some lubricant through the threads until you don't see any shavings coming out on the tap.

 

[90gst_sean]

Even being a new turbo, you dont think its a heat issue? I know I've heard Defiant preach on about how our cars were made to take the temps, but I just dont have that kind of faith.

Thanks though, its good to see some local faces around here; there just arnt that many of us.

What sort of lube should I use? Penetrating oil doesn't seem to help much in this case. Motor oil? Or do I need cutting oil for the best results?

 

[Black Venom]

Do these bolts go in by hand nice and smooth then seize after heat cycles, or is it a pain to get them in, in the first place?

I recently bolted down a JM Fab heat shield using the Stainless bolts, even with the added protection of copper anti seize it's frozen one within under 3K miles. All bolts went in nice then snugged down with an allen head.

 

[GVR4592]

Do these bolts go in by hand nice and smooth then seize after heat cycles, or is it a pain to get them in, in the first place?

I recently bolted down a JM Fab heat shield using the Stainless bolts, even with the added protection of copper anti seize it's frozen one within under 3K miles. All bolts went in nice then snugged down with an allen head.

Stainless bolts are a bad idea in high heat exhaust applications, stainless expands a lot and usually results in the bolts seizing or just breaking.

 

[GVR4592]

Even being a new turbo, you dont think its a heat issue? I know I've heard Defiant preach on about how our cars were made to take the temps, but I just dont have that kind of faith.

Thanks though, its good to see some local faces around here; there just arnt that many of us.

What sort of lube should I use? Penetrating oil doesn't seem to help much in this case. Motor oil? Or do I need cutting oil for the best results?

I'm sure the high heat doesn't help the situation, but I have the stock heat shield using all of the factory bolts and I haven't had any problems. I take it off at least a couple times a year to check the turbo bolts.

As for lubricant, I would use whatever you have available. I've used penetrating lubricant(kroil, pb blaster), motor oil, cutting oil, and I haven't really noticed a big difference in any of them.

 

[Black Venom]

Stainless bolts are a bad idea in high heat exhaust applications, stainless expands a lot and usually results in the bolts seizing or just breaking.

I wouldn't go out and buy them for this application because of that. It was foolish to think that since they came with the heatshield I would be fine.
I don't want to get too off topic in this thread, but do you have any suggestions on replacement bolts other then from satan?

 

[90gst_sean]

Do these bolts go in by hand nice and smooth then seize after heat cycles, or is it a pain to get them in, in the first place

Nice and smooth the first time, as for the turbo shield bolt 3000 miles ago. Im sure it will be harder now.