Contamination in coolant

[barc77]

So, I just got this 924s a few weeks ago, and have only driven it ~ 100 miles.

I think I may have oil mixing in my coolant reservoir? The coolant was low, so I pull off the cap, and there is some tan milky stuff in a couple places and on the bottom of the cap, almost looks like curdled milk. I pulled some of the coolant out with a syringe, and it is a light greenish brown color.

I did not think to check this when I bought the car (rookie mistake, I know). The car runs well (so far) and there are no leaks that have dripped onto the floor under the car. The guy I bought it off of seemed pretty honest. He gave me ~ 15 years of maintenance records. And had recently changed the clutch, not sure if that would have any effect on anything.

Am I looking at a major problem here? Are there any other simple things I can look at that might help diagnose the problem?

Any advice is appreciated.

Thanks,
Barc

[John_AZ]

Hi Barc77,

This is not serious if you do the work now. The 1987 924S is known for the oil cooler housing seals to leak.
Get a kit on Pelican or just order each piece of the kit individually and save a couple of dollars.
Get the aluminum crush washers for the OPRV and Oil pressure sender or they will drip.
Get the Late OPRV alignment tool or beg to borrow.

Tips.
You do not have to remove the exhaust manifold. When you remove the oil cooler, memorize the position of the cooler and how you had to twist it to get it out.

Test the oil cooler for leaks.
Put a silicone sealer in the groove of the housing before you put the big seal in to cover the corrosion pits--use an artest paint brush.
Change 2 "O" rings on the OPRV. Yes there are 2.

Flush the coolant hoses with a squirt of quality dish soap and remove and rinse the coolant reservoir.
Use distilled water to mix with phosphate free antifreeze.

Easy--just dirty and messy when the coolant and oil fall on your face.

GL
John_AZ
1988 924S 60K + 1987 924S 114K

[Rasta Monsta]

Originally Posted by John_AZ

use an artest paint brush

For the last time, STAY OUT OF MY PAINT BRUSHES!

[barc77]

I think I may need some Artest money to get things in order on this car .

Thanks for the advice John_AZ

I have the 944 hayes guide, but have not looked at the oil cooler part yet.
I will need to find step by step instructions somewhere for this job. Anyone out there have a link to a write up. Something with pictures would be very helpful.

Besides the late OPRV guide (that does not appear to be in stock) ,are there any other special tools I would need to attempt the seal replacements?

Thanks

[Grandad#3]

Hi Bark77, John's advice is great. You might want to check out the link below for Maintenance.

Clark's Garage Shop Manual Index

Cheers,
Larry

[John_AZ]

Originally Posted by Rasta Monsta

For the last time, STAY OUT OF MY PAINT BRUSHES!

Thanks Rasta, That's funny.!

I take a day off to do research (see the snow in Prescott) and come back to "mybad" spelling of artist..

[John_AZ]

Originally Posted by barc77

I think I may need some Artest money to get things in order on this car .

Thanks for the advice John_AZ

I have the 944 Haynes guide, but have not looked at the oil cooler part yet.
I will need to find step by step instructions somewhere for this job. Anyone out there have a link to a write up. Something with pictures would be very helpful.

Besides the late OPRV guide (that does not appear to be in stock) ,are there any other special tools I would need to attempt the seal replacements?

Thanks

barc77,
Thanks for the reply.
The Haynes manual is often very basic.

You need the OPRV alignment tool to prevent the OPRV valve from binding in the block. The tool screws into the OPRV oil cooler housing and then you tighten the housing nuts.

Here are a couple of "official" TSB (Technical Service Bulletins) on the OPRV and Housing.

http://www.944online.com/pdf/oilcoolertech.pdf

AND------------------OPRV "O" ring replacement





If you search past posts for the OPRV or oil cooler housing you will find many well written posts (mine are infamous) on the procedure as well as Clarks

GL
John_AZ

[barc77]

Thanks again everyone for all the advice. I just printed a bunch of stuff out from Clarks.

My oil pressure gauge inside the car acts crazy all the time. It will sometimes peg at 5, even at idle, then will start bouncing back and forth very fast maybe 2-3 times a second from 0 to 5.

I am going to replace the sender, from other posts it sounded like that could be the problem.

If the OPRV is bad, would it have that effect on the dash gauge ?

[HondaDustR]

Here's the correct tool, or you may be able to borrow from someone.
00072192621, 000.721.926.21, 000-721-926-21, p9262, p-9262, Oil Cooler Alignment Tool

You may want to remove the exhaust manifolds anyway. It is possible to do it with them on, but it's a PITA, especially re-assembly, since clearance is really tight. It's really hard to hold the housing against the block and get the first bolt started. These are not bolts you want to cross thread.

[John_AZ]

Originally Posted by barc77

Thanks again everyone for all the advice. I just printed a bunch of stuff out from Clarks.

My oil pressure gauge inside the car acts crazy all the time. It will sometimes peg at 5, even at idle, then will start bouncing back and forth very fast maybe 2-3 times a second from 0 to 5.

I am going to replace the sender, from other posts it sounded like that could be the problem.

If the OPRV is bad, would it have that effect on the dash gauge ?

When you remove/replace the oil pressure sending guage, be very careful of the 2 hollow terminals. They crack very easy.

Have new crush washers for the OPRV valve and the oil pressure sender or you will see drips.

Clarks and this link have OPRV housing seal information.

944 Oil/Water Heat Exchanger Seal Replacement Procedure

A couple of additional tips. Lube the 2 green seals on the cooler before you install and press into block. If not lubed, the seals will "roll" and leak.

As mentioned above, replace 2 "o" rings on the OPRV and use a Permatex RTV thinly applied in the oil cooler housing main seal groove. Pitting in the groove needs to be sealed.

If you do remove the exhaust manifold, get 4 exhaust manifold gaskets, 2 exhaust manifold flange gaskets. You might have to cut off the 6 rusted bolts and nuts on the flange--Ace hardware.

GL
John_AZ

[barc77]

Thanks again everyone for the advice and links. After getting a ballpark quote of around $700 to have a shop do this work I am going to try it myself.

A couple more questions before I get started....

I am reading in one of the tech bulletins that the OPRV is a non serviceable part, is this correct? How can I replace an internal 'o' ring with out taking it apart, or am I not reading this correctly. I believe I should have the one piece, since it s a 87 924s.

Also, it says to replace the the connecting rod nuts at each repair. Where are they located, and is this necessary?


I guess I will see if I can even get the manifold off to start.

[ScoobySteve]

Originally Posted by barc77

Thanks again everyone for the advice and links. After getting a ballpark quote of around $700 to have a shop do this work I am going to try it myself.

A couple more questions before I get started....

I am reading in one of the tech bulletins that the OPRV is a non serviceable part, is this correct? How can I replace an internal 'o' ring with out taking it apart, or am I not reading this correctly. I believe I should have the one piece, since it s a 87 924s.

Also, it says to replace the the connecting rod nuts at each repair. Where are they located, and is this necessary?


I guess I will see if I can even get the manifold off to start.

You might want to call a couple of shops. This is a VERY standard 944/924S procedure and they should have no trouble giving you a fairly exact number. It's like calling and asking about a clutch job or a belt service -- it's that common.

I believe you mean the connecting rod bearing bearings. On these motors it's a good general procedure to do them around 130k - 140k miles. However, the real danger is when coolant gets into the oil, not the other way around. Coolant is not a very good lubricant (despite feeling slippery and being non-evaporative) and the rod bearings are the most susceptible to failure. So you might want to check the oil just to make sure. Fortunately, the oil coolers usually fail with oil in the coolant and not vice versa since the oil pressure is much higher than the coolant pressure.

Oh, these cars are not cheap to maintain. Of course, there's very little depreciation expense so just put gas in it, stay on top of these things, and have fun.

[John_AZ]

Originally Posted by barc77

I am reading in one of the tech bulletins that the OPRV is a non serviceable part, is this correct? How can I replace an internal 'o' ring with out taking it apart, or am I not reading this correctly. I believe I should have the one piece, since it s a 87 924s.

The "Repair Procedure" is on Post 7 ^, page 2 of the TSB.


GL
John_AZ