Gasket swapping and retorquing

[architechnik]

I was wondering if anyone else in cold-weather areas have had to retorque various fittings.

Notably the oil return line for the turbo has pretty much lost its seal over the past couple months and now it sprays a good bit of oil on the highway. I checked the bolts and they could nearly be tightened by hand. I gave if a few turns to keep it snug until I can swap everything out this weekend, but I decided to check everything else.

The same thing on the exhaust manifold-to-block and turbo-to-manifold. Is this common for cold areas? Should (Can) I use threadlock on any of these parts (esp exhaust) when I actually retorque everything to specs?

 

[romeen]

I've never had the problem you are describing. If anything heat (not cold) will cause the bolt holes to expand a little but these bolts should not be coming loose on their own just from the temperature changes.

I would definitely NOT use loctite on any exhaust related components. Just the opposite. I use high temp (copper based) anti-sieze on the fasteners to avoid future problems with removal or broken studs/bolts.

For the turbo-manifold bolts are you using two oem cup washers per bolt in the proper orientation (concave sides facing eachother)? If not that may be why those bolts are vibrating loose.

For the oil return line it sounds like you may just need to replace the oem gasket. Mitsubishi does not say to use any RTV in conjunction with the gasket but I have done this with good results. Just a little bit on either side of the gasket is all you need if you want to try it. Also make sure that the return line-pan bolts are not stripped. And don't forget the 6mm crush washers between the bolt head and flange (1/4" crush washers will also work).

 

[architechnik]

I figures it was the combination of cold and heat, once I drive for a while then it contracts in the extreme cold, then once again. This is a DD with a one hour commute.

I thought the lock-tite was wrong. A local shop that I previously decided not to patron anymore suggested it.

The turbo-manifold bolts are ARP stainless with single stainless lock-washers. This may be part of the problem. I'll try replacing those washers with a double copper or OEM set to see if it holds better. I noticed one of the points is actually stripped, so I'll also tap in a helicoil.

I already bought the turbo mounting gasket set to replace everything at the same time. I'll try a bit of high temp RTV. The pan nuts seem to be in pretty good condition, as it increased tension right along with each bit of a turn. I'll inspect everything once I can get the turbo off and look at any real leak locations or spray pattern in case it's actually coming from somewhere else.

 

[romeen]

The turbo-manifold bolts are ARP stainless with single stainless lock-washers. This may be part of the problem. I'll try replacing those washers with a double copper or OEM set to see if it holds better.

I would replace the ARP washers with the oem washers that you can see here:

EXTREME PSI : Your #1 Source for In Stock Performance Parts - OEM Turbo to Manifold Washers : Mitsubishi Eclipse 90-99

If you look closely you can see that each washer has 2 dots or dimples on one surface. Your supposed to use 2 stacked washers per bolt such that the dimpled sides face away from eachother. In other words one dimpled side of a washer facing the bolt head and the other washer's marked side facing the exhaust manifold. What you can't see in that picture is that the washers actually have a concave side and a convex side. The dimpled side is convex or "pointy" for lack of a better description. When the washers are stacked properly it puts tension on the bolts to keep them tight.

You might also try torquing the bolts to spec while the engine is warm. It would be a good idea to retorque them after the first heat cycle, especially the turbo-manifold bolts.

 

[turbosax2]

Read this thread and see if you still want to keep those arp turbo bolts.


And here are the Mitsubishi part numbers for the bolts and washers.

MR187699 (4) - Turbo to manifold bolts - $4.68 - $18.72
MR187848 (8) - Turbo to manifold washers - $1.13 - $9.04

OEM Mitsubishi Parts

 

[romeen]

That's a good link Eric . My initial thought was to recommend replacing both the ARP bolts and washers but I figured with ARP's reputation they might be good. In hindsight, stainless steel is more brittle than other forms of steel so apparently not a good idea as evidence in that thread.

 

[architechnik]

Wow, I wish I had read that thread about the SS bolts previously. I bought them from ExtremePSI and now I wish I hadn't dropped the extra cash. I figured with the stripped threads I found on those bolts when I bought the car a little extra hardness might be the way to go especially with the advertising that says they are considerably stronger than grade 8 OEM.

Does anyone know if ARP has started an investigation into these scenarios? I have had them on there for about 4 months now and I'll probably keep them on until they bust. I have the old set that I used a die on, but some of the threads were completely gone so there was nothing left to cut into. I still have the washers as well, so maybe that swap will work.

 

[romeen]

I figured with the stripped threads I found on those bolts when I bought the car a little extra hardness might be the way to go especially with the advertising that says they are considerably stronger than grade 8 OEM.QUOTE]

The oem bolts are actually incredibly durable and are harder than grade 8. I believe they are grade 10.9 or possibly even more.

 

[turbosax2]

The oem bolts are actually incredibly durable and are harder than grade 8. I believe they are grade 10.9 or possibly even more.

They are grade 11.

 

[architechnik]

So would you guys consider the advertising on ExtremePSI to be false or at the least misleading? Could you guys verify that the OEM strength is actually above 10, either from Mitsubishi or another retailer with accurate information?

I'm going to write E-PSI an email and express my concern. I don't want a situation like this to continue.

 

[turbosax2]

The oem bolts are definitely grade 11. It says 11 right on the bolt head.

I don't know if I would consider this false advertising, but I'm not a lawyer. We all know arp makes great products. I guess this one just doesn't work like it's meant to.