Ed Scherer

Got under my car for the first time in quite awhile yesterday. Had a few things I wanted to do, but while I was under there, I also wanted to see what I could discover about a slowly worsening coolant leak problem I've been experiencing for awhile (months, and perhaps even a little wetness I'd see on top of the front of the oil pan for quite some time).

I'm seeing what I'm starting to think might be evidence of two separate leaks. I could use a little help from those of you who might have experienced and dealt with similar issues before.


Here's what the bottom of my under tray looks like now; this might provide useful evidence (Zerex G-05 chalks nicely!):

(Click any of the photos in this post for larger versions.)





Leak Evidence Site #1

This one really took me by surprise, because I hadn't noticed this at all before, and I suspect it might be responsible for the majority of coolant loss.

It looks like coolant is somehow finding its way into the right radiator fan and then being flung around and coating various surfaces (hoses, front side of A/C compressor clutch, etc.). Strange thing is, I just can't seem to find the source of this coolant. The hoses above (fat upper radiator hose and the smaller hose that I think goes to the coolant reservoir) seem just fine and there's no evidence of "chalk rivers" (there is some flung chalk) on them.

So... is this perhaps a symptom of a radiator leak, with small amounts of coolant being blown back into the fan, and then flung by the fan? I don't see any chalk on the radiator fins, but I think I see a little chalk along the right end (is this what's called the "end tank" area?)

Photo showing all this:




Leak Evidence Site #2

The second leak site has been active for longer, but I think the leak rate might be increasing. I'm seeing the greatest amount of chalk around the PKsn'r.

Some photos:






Additional Observation

I looked back at my photos from a couple of years ago when I did the last timing belt job and installed the PKsn'r. Note the set screw "plug" RTVed into one of the holes in the water pump right above the piston in the PKsn'r? I remember worrying about that technique (it was done using the set screw and per the instructions that came with the PKsn'r) and shared my concerns about whether or not that was a good idea (I wasn't the only one; see the posts I quoted in that post). Might that be the source of the leak?



For comparison purposes, here's what things looked like a couple of years ago before the new water pump and PKsn'r:





My Questions

Feel free, of course, to offer any advice based on what I've said and shown. Some specific questions I have:

• For "leak site #1," is this "coolant chalk in the fan" a typical symptom of a radiator leak?
• For "leak site #2," has anyone else gotten this kind of leakage on and around a PKsn'r? Perhaps due to leakage at the "set screw plug"?
• Can you get to that "set screw" (originally the idler pully post) by only removing the right timing belt cover (left viewed from the front of the car)? (I suspect the center cover needs to come off; arggghhhhh!) Maybe just be able to see if that's the leak point, at least?
• Do I really need to deal with either of these before the 180-mile-each-way round trip to/from Wichita for the OCIC? I've been living with at least one of these leaks (the one by the PKsn'r) for quite awhile, but I think the radiator-area one is fairly new. Do those tend to get really bad really fast, or am I likely to be OK for awhile?
• Are there further diagnostic techniques I should employ to narrow down the leak source(s)? I guess I could run the engine up to temperature and look for wet coolant; it's so damn hot in the garage that I've been trying to avoid that, though.

I'll wait for a few replies before asking some further questions (e.g., about radiator replacement; I believe mine with the A/T '90 is both a coolant / A/T oil cooler version).

I've got very limited time to deal with this before the OCIC in Wichita, so I any pointers that would save me time would be greatly appreciated.

borland

Looks like at least two leaks, radiator and water pump.

The water pump has a weep hole for the shaft seal located on the left (driver) side. Have you inspected it for coolant/coolant residue (with side cam cover removed)? If not a shaft seal leak, then the pump gasket is likely the problem. You might be able to visually check the PKsn'r (PKT) coolant plug from one side (side cam cover removed).

Might be good idea to pressure test your coolant system. Autozone or O'Reilly might have pressure tester to loan, or you could rig up something.

Your oil pan gasket looks toast too.

borland

Also, I've never used Zerex G-05, so not sure about that chalky residue. I assume you've already check that you don't have any similar sediment in your coolant reservoir.

Ed Scherer

Thanks for the replies, borland.

Haven't had the covers off yet. Might not do that myself, given time constraints, but it seems like a reasonable next step.

That sounds reasonable, too. Might also leave that for the shop to do.

Yeah, that was rather disappointing to see, too. That gasket is about five years old. I was hoping it would hold up longer. At least that's a deferrable issue.

Yeah, I just replaced the reservoir about a week or two ago. Nothing unusual in the old one (but yellowed and a bit crusty; I believe it was original). Nothing unusual in the coolant that I siphoned out prior to removing the old reservoir.



At this point, I guess one of the things I'll need to decide on ASAP is whether or not to order a new radiator right away. I just want to make sure I have all the parts on hand since my window of opportunity to have this stuff taken care of (whether or do it myself or hand it off to the shop) is rather small. I really want to have all the mechanical stuff done by next weekend so I have that weekend to take care of cosmetic stuff before the OCIC.

borland

The side tanks are easy to remove and install new gaskets. That's probably what's leaking, especially since it's leaking on the transmission cooler side. The coolant runs down the side and pools at the bottom where the fan wicks up some.

You just need to find the forum thread that addresses how to remove the side tank without bending up the tabs. The tabs will break if you try bending them up. You need to spread the tabs out to release the side tanks. If you don't have time to fix the side tank, then you might want to get a price quote from Sunset.

For the oil pan gasket, the silicone rubber gasket is the way to go. In 2010, I did a how to which details the bolt tightening without a torque wrench and also making tabbed washers to captivate the bolts so they don't work loose.

Have you checked the radiator drain plug for leaks?

Here's the link for the side tank repair..

https://rennlist.com/forums/928-foru...king-tabs.html

And the thread addressing the o-ring sizes for the transmission cooler..

https://rennlist.com/forums/928-foru...side-tank.html