Exhaust header removal

[djnolan]

Trying to replace the oil cooler seals myself in an 85.5 automatic...

Removing the exhaust header appears absolutely necessary. Is this correct?

If so does this mean dropping it down or removing it completely?

If so, is removal of the studs required to get the clearance to drop the thing down, or can just the bolts be removed?

Since I have an auto there are a couple of tranny cooler lines that run on top of the coolant pipe and heatshield. To get the exh studs out do I have to remove all of these pipes and heat shield?

Any other gotchas or while-you-are-in-there's anyone wants to share with me?

85.5 Automatic -Guards Red

[bud9344]

CAUTION !
I did replace my 85.5 944 without taking the exhaust headers out. Mind there is not a lot off room to work in that area.
Just remember to Install the Oil Pressure regulator before you tighten all the bolt.
Good Luck

---------------------------
Bud

[bud9344]

Sorry forget to mention.
I have an updated oil pressure regulator on the car.

[porsche4life]

I pulled the headers on my car and all it took was pulling the nuts off. Avoid pulling it if at all possible because i thought i would never get it back on. My car is manual also so i dont know how much that changes.

[djnolan]

I will give it a try since i already have it unbolted. there is a bracket from the header to the engine mount that also looks like it needs to be unbolted.

Does the header have to be unbolted from the exhaust pipes too?

Is the oil pressure regulator the large hex bolt on the front of the housing?

[porsche4life]

If you want to get it all the way out yes you do have to unbolt ti from the exhaust. I had to drop the cat too.

[HondaDustR]

Yes, you would need to unbolt the headers from the Y-pipe in order to remove them.

I would highly recommend removing the headers, as there is just barely enough room to work under there with them on. Although it's possible to do it with them on, it's extremely challenging in both dexterity and patience to get the cooler assembly back on without screwing up the alignment of the cooler parts inside the housing, not to mention holding the darn thing on the block while trying to maneuver the first bolt into the hole without cross threading it (very easy to do in aluminum), and without really being able to see what you're doing, and barely being able to fit both hands and a bolt under there (holding the bolt with 2 fingers and dropping it a million times), and....well, you get the idea.

[djnolan]

I am going to try to remove the studs and see if it will move far enough without having to unbolt the flanges. The flanges seem like they would be a real pain to reseal and realign.

[Slam]

Did mine with the header in situ - but I've got small hands. You need some good wobble extensions and lots of patience. When time comes to reinstall the cooler, pop in the lower bolts to align the housing and then work from up top on the last couple.

[djnolan]

with the header on I can see getting the cooler housing bolts out. I don't see how the cooler housing can be taken out to work on it however with the wp or ps pump in place. Did you replace the seals without taking the cooler housing out completely?

[Slam]

My car has no power steering. But I believe the ps pump has gotta be moved at the very least. I did take the cooler right off the car to service it. HTH Have you had a look at Clark's and read up on shimming the element?

[djnolan]

roger on the shims. thx.

[HondaDustR]

The power steering pump should be unbolted and hung out of the way.

See the procedure here. http://www.clarks-garage.com//shop-manual/lube-01.htm

The cooler housing will come off with the headers on. The cooling element is separate from both the block and the housing, and simply sits inside the housing practically flush with the gasket surface. It just takes a little maneuvering to get it to come loose from the block...oh, and be prepared to get spilled on.

[djnolan]

thanks HondaDustR. that helps.

[Slam]

My $.02 on shimming: I've got the early car with the early housing. I know that Porsche would have you update your housing and then use plastic shims to set the element clearance (so it sits properly in relation to the block and housing) but I just simply reassembled using the OPRV alignment tool and tossed the plastic shims away. I figured that the thing had been leak-free for 20 years and it had been the old seals that failed, not an alignment problem.

(Ducks behind bent fender)

[HondaDustR]

Oh, and one more thing. Be careful with the oil pressure sender connectors. Apparently they are kind of fragile. I have seen several threads where people have broken them off.

[djnolan]

Since I started this thread I thought I should report back...

To replace the oil cooler seals on a 85.5 N/A it involved the following:

Follow the procedure on Clarkes and...
1. Drop down the powersteering pump and resovoir.
2. Remove the right stabilizer bar bracket.
3. Not necessary to remove the exhasut header but removing the heat shield gives more room to work.
4. Work from on top and underneath to remove the oil cooler heat shield and cover dropping both out the bottom thru where the PS pump and stabilizer bracket were removed.
5. A very good assortment of swivels and wobbles will be needed to get the oil cooler bolts out and back in.

There is also another thread on oil pressure relief valve consulted due to some questions in this area.
http://forums.pelicanparts.com/showthread.php?t=382099&goto=newpost

At the same time you might consider replacing the following:
1. cooling system hoses since the system will be drained.
2. stabilizer bar bushings since it will be partially disassambled and you will be underneath.
3. Power steering hoses that are leaking.

[onZedge]

If you have the cast-iron headers, they can come out from above, provided:
- remove the six header flange bolts
- you take the exhaust manifold studs out (at least the 2-3 header studs)
- remove the 2-3 header first, and then the 1-4 header (it doesn't look like it makes sense to do it in that order, but you'll understand if you do decide to do it)

I just R&R'd the oil cooler yesterday. I had these off the car: cam tower, head, exhaust manifolds, PS pump, water pump, pressure sender and heat shield and it was STILL a a little bit of a PITA. Suprisingly, the PS reservoir being in the way was not an issue.

My $0.02: It just seems insane to me that anyone would try this without at least removing the headers.

[pauloregon]

There's always that theory that you can save time by not removing the headers from the car. You can try to get the cooler housing out of the engine compartment, possibly damaging the cooler element, etc. Maybe the shop guys can do this, but for the avg DIY guy, it pays to take your time and do it right.

I did my oil cooler over the recent memorial day weekend. I ended up removing the entire exhaust assembly (only 6 bolts, the O2 sensor and CO test pipe) before removing the headers. Headers come off easily. And, you can get at the oil pressure sender from above with a normal 24mm wrench with the headers off. Oh yeah, with the headers off, you can easily move the new, clean, beautifully restored oil cooler assembly back into place.

After 10+ years of working on my 944 (and my BMW 325), I found that taking your time, having the right tools and reading the procedures are key to having a good experience.

[onZedge]

^^^+1