Can the rear timing cover be removed and replaced without pulling the head?

[MarkIII4Me]

I need to weld (or replace) the rear timing cover where the turbo's coolant line return goes. The previous owner ran a oil cooled only turbo and welded over the coolant return. I drilled and tapped it for an NPT fitting. The walls weren't as thick as I had thought and now there is a small hairline crack where the fitting was tapped.

It's easy enough to get to, but nobody I know has the correct equipment to weld aluminum, so I'd need to either have the car towed or removed the timing cover and bring it to someone. If I remember correctly, the rear timing cover was machined with the block and the head sits on it. So can the rear timing cover be removed and replaced without causing leaks, or do I have to have it repaired while it's still in the car? I'd really like to avoid using epoxy as it would only be a temporary fix and make a mess when it comes to getting it welded down the road. Plus it's only several inches from the exhaust manifold, so any epoxy won't last long.

Thanks.

 

[IwantMKIII]

no, head must be removed, just did it this past summer, it sucks.

 

[jetjock]

It'd be easier to weld even if you have to tow the car. And be careful when tightening NPT fittings because they're tapered. Don't run them in very far on thinwalled or soft material.

 

[MarkIII4Me]

^
Oh, I know, but the integrity of the threads were questionable, so I wanted to make sure the fitting was properly seated. Unfortunately, I wasn't used to the feel of liquid teflon at the time, and my normal torque was about 1mm too much. It sucked. Just as soon as I was done tightening I heard a faint "click". Live and learn.

 

[Devin LeBlanc]

MHG? should be able to replace it without removing the head. We reuse MHG's all the time on our race engines.

The most important thing is to make sure the deck hight of the front cover matches the hight of the block otherwise its going to give you issues once its installed.

 

[adampecush]

No, the head doesn't have to be removed, but you will have to machine the sealing surface of the new timing cover to be of equal height to the one you are removing. Use FIPG at the locations indicated by the TSRM when re-sealing.

Currently, I'm running on a removed/replaced timing cover without issue.

 

[MarkIII4Me]

^
So if I removed the current rear timing cover and repair it, I can reinstall it with no issues as long as I use FIPG where needed?

 

[TweeT91109]

^
So if I removed the current rear timing cover and repair it, I can reinstall it with no issues as long as I use FIPG where needed?

thats what he is saying yes. But like you stated, you don't want any problems later down the road, and with the exhaust manifold being right there, it wont last long. Even the high temp stuff wont last.

 

[IJ.]

Can't see how it can be done with any degree of success, the dowel pins in the block mean you have to slide the cover in so any sealant will be squeeged back towards the block.

It's hard enough getting a 7M head to seal when everything is perfect this is just a recipe for leaks...

 

[MarkIII4Me]

^
That's what I was afraid of. Better safe then sorry. I'll get it welded, whatever it takes. The whole reason I dropped $4500 on my longblock is because it was heavily built and previously ran for 3500mi with no leaks. I pullled my old engine from the machine shop before it was even assembled and sold it off because I didn't want to deal with the headache of issues down the road.