vetter59

Hi guys, I have a 1985 928 5spd car and have enjoyed reading and learning from the 928 forum on Rennlist- you all are a wealth of information.
I have currently have a troubling oil leak at the thermostat housing on the engine block -left side, and am looking for some advice.
I have oil dripping from the thermostat housing blowing back onto the exhaust. I got the car up on jack stands for inspection of the problem and thought it could be the oil pressure sender. I had previously rebuilt the oil cooler lines that go to l/h side of radiator in June, with high temp blue Aeroquip hose and hyd. crimps, and they appear to still be dry. However while inspecting- I found the lower cooling line - male/male -fitting that goes into block next to oil thermostat somewhat loose, and after removing it, I found several threads stripped out, on the alum. block side. Currently there are about 3 good threads left and I am able to tighten the fitting, but don't feel comfortable with driving it like this.
I am asking if anyone has had this problem before and what might be a proper fix? Is there a 22mm X 1.25 time-cert or heli-coil kit available this big? And can you get a angle drill with bit in there?
Any help or ideas greatly appreciated.
Thanks

Mrmerlin

what i would do is remove the fitting thats loose or leaking ,
clean the threads very well,
then get a new sealing washer that has a wider face, try NAPA
then mix up some JB weld install the new washer,
then coat the threads of the girdle and the upper part of the fitting,
screw it into the block and let it cure for 24 hours then install the hose

vetter59

I have been making calls all day, and that seems to be the consensus- clean well first , and install wet with JB weld - I am wondering if I should maybe put some release agent on the fitting? - if I ever want to remove it again - or put it dry and forget taking out again. I do still have about half the threads remaining, and can tighten it.
I actually did find a friend who has that size Time-Cert 22mm X1.5 pitch- Dave Brown at RennGruppe Motor Sports in Lexington N.C. , he mainly cares for vintage race cars, and he says he has the kit if I want to borrow it, that size he said is used on 962 case repair, but I will only try this method if I can get the tooling in there at the correct angle. Once you drill your committed.
Thanks for your input.

heinrich

Let me rephrase. Do not use JB Weld. Timecert or helicoil or tap to next size.

Mrmerlin

A time cert would be the best way to fix this... BUT

I have fixed a few of these fittings and so far no leakers.
The key is to get a new sealing ring that has a wider face,
this should cover the damaged area,
Napa has these sealing rings take the fitting to match it up

NOTE put the JB weld into the void after you have screwed the fitting in a turn or two,
the fitting doesnt ever have to come out , they are glued into the girdle with green locktite at the factory.

If this fix wont hold then you have to pull the engine to get a drill into this area, if this is the case then the JB weld can be drilled out along with the surrounding metal

For anyone else reading this , it should be noted if you take off the oil cooler lines then the fitting in the block should be counterheld,
they should not be loosened as this usually will fracture the threads in the girdle

vetter59

I agree with all the above post's -a time cert would be the best way to go - however I do not want to pull the engine for this only reason when everything else is fine. With the engine in the car- it is very difficult to drill the hole straight. So it sounds like the consensus is to go with JB weld repair.
The last question I have is: Without a washer I can get 2-3 good turns on the remaining "Good" threads with the fitting. If I put the washer on ,because of it's thickness I can only get 1 1/2 turns - so what would be the stronger repair, without leaks? Wouldn't the JB weld squeeze out the side when tightened and create a good seal? Also should I dab the inside of the housing behind the fitting [with thermostat removed for access] with JB weld for higher strengh?

vetter59

BTW - I did find a tool supplier who can get the 22mm X 1.5 pitch , price is $140.00 plus $10.00 shipping. For anyone needing this large size - Wotco Tool.com

Mrmerlin

I would see if the machine shop can cut the threads down further on your fitting so the threaded area is longer then also fit the larger faced washer ,
Or buy a longer fitting dont know where you would find one though.

Be careful with the JB weld you dont want any to get to the bottom of the the threaded area on the fitting