Dwayne

THANKS for the pictures, Bill.

I've located the sealing ring and took it out. It's never been replaced since I've had the car because I didn't even know it existed. We've had the car since 1996. All the rubber is gone - only a thin strip of rubber between the ring and the housing mating surface. It looks corroded but not to the point where it would account for all the stuff I found when I drained the block/radiator. It will be interesting to see what the new one looks like. I took some pics and can post. I'm going to order a replacement one today and an extra thermostat to boot, re-install and see if there's any difference (probably tomorrow before I get the parts).

Charley B

Dwayne, what was the consistency of the stuff you got out of the cooling system? Did it seem to be metal fragments, mineral build up or something softer such as gasket or rubber? If you have already explained that, I apologize.

Dwayne

Charley,
It appeared to be metal fragments rather than mineral buildup. Although I did not look closely - should have taken the time to look closer while I was taking pictures. If it was rubber, I would think it would have floated to the top, these specks sank to the bottom of the container pretty fast. THANKS for the question.

Charley B

I'm sure you have checked for cross contamination between water and oil. You're not losing any water from the system and your satisfied the head gaskets are intact. Right?
I think those head gaskets are less than a year old so it's quite unlikely that would be the problem.

hupp

When replacing the thermostat, insure that all of the parts are replaced in the proper order. Some have made the mistake of not installing the o-ring/seal correctly relative to the thermostat.

Thermostat into the thermostat housing/water bridge first, then o-ring, then bolt on cover. Some have reversed the o-ring/T-stat order which will cause the thermostat to bind.

Dwayne

Right! The head gaskets I put on this summer. I have not cross contamination and the car does not use coolant.

I ordered the seal and a spare thermostat today - should be here tomorrow and I'll install tomorrow night and give it a try. Tonight, I'm re-connecting the heater hoses up.

Dwayne

Right on!

Dwayne

OK...got the new sealing ring and spare thermostat today! THANKS to Jim at 928Intl !!

Here's pics of the old sealing ring that came out:




And the new ring compared to the old one:



I ordered another thermostat even though the current thermostat was only about 4 months old. I'm glad I did because the new one seems to be a better design, beefier and I like it - "Made in Germany" stamped on it (Behr). The previous one was stamped Motorad. THANKS for the suggestion Mrmerlin! Here's a couple of pics of both thermostats (the Behr one also has an arrow stamped on the face to direct orientation of the thermostat when putting it in. The new Behr is on the left.



After putting it back together and topping the coolant off, I took it for a drive and also ran the heater to get full circulation. Unfortunately, I did not see much improvement from previously. Here's a pic of where the temp goes when I'm driving about 45 up a slight to moderate grade for about a mile or two:


It's just a little better than before the new seal and thermostat and still seems high to me compared to when I first replaced my radiator about 10 years ago and the temp needle never ever got to half way (always used to be just above the 1st white line.

So, I'm thinking the temperature sending unit or radiator must be the culprit. I'm leaning toward the radiator. When I drive around town the needle hangs around midpoint or above but not below. Same with highway speeds. When I drive up a slight grade the needle moves up closer to the 2nd line. When I drive at highway speeds and turn on the heater, the needle actually goes down to midpoint. If the sending unit was bad, and the thermostat keeps the temp fairly constant, it seems the needle would stay put at an incorrect temp reading. But since temps are changing depending on whether I'm driving straight and level, up a slight grade or with the heater on, I'm thinking the flow in the radiator may be partially obstructed to the point where even when the thermostat is wide open, the cooling system can't keep the temp steady when driving conditions change.

Looks like I'll be getting another radiator but I'll probably replace the sending unit anyway so I'll have a spare. THANKS for reading...opinions welcome!

Mrmerlin

Ok Dwane lets do a bit more investigation , get your hands on a IR temp gun they have them at Sears and i think also harbor freight, you want to check the top hose after things get warmed up and also the radiator at various places see if it is truly hot, if the temps are at 180 to 185 then i would say that your golden.,
I have another car that was running almost in the red zone and the PO had already replaced the radiator and thermostate, still indicating hot so i got a IR gun and guess what the whole engine/radiator was running at 195 and that was what the thermostate was stamped. i opened up the gauge and rebent a part now it runs less than half. Dont replace the radiator yet , also to consider is the temp sender, try removing it and cleaning the connector , check to see if the sender might be corroded.

Give the spare thermostate to the trash man, it looks like a cheap knock off

G Man

Before you replace the radiator I would have it checked out to make sure it is not plugged up on the inside with those little flakes you were getting out during the flush. The plastic tanks can be removed and the core "rodded" out to make sure the tubes are free flowing. Also, how is the operation of the fan clutch? Could be it is not working like it should and not drawing enough air through the radiator. I know there have been posts in the past that talk about the impeller on the water pump failing and creating an overheat situation. I think this is found with the plastic impeller version of the WP. Hope you get it sorted out soon. I had a cool running condition awhile back. Check out the pic in my lilnk.

https://rennlist.com/forums/showthre...ght=thermostat

Dwayne

AHH YES! THANKS for reminding me, Mrmerlin! Jim B. also suggested getting an IR temp sensor and do the very same thing you suggested. I can do that this weekend before jumping the gun on a new radiator. My wife and I are driving to Lancaster tomorrow so I can stop by Harbor Freight or Sears. I forgot all about this course of action!!

Dwayne

Hi Jim,
I checked out your post....that's a first for me - never seen a thermostat self-destruct like that!

Can I actually take the plastic tanks off and inspect the core or does a radiator shop have to do this??

The main fan seems to be working - it spins when the motor's on. When the motor is off, it feels viscous when I turn it by hand. Is there a procedure for checking for proper viscosity??

Mrmerlin

If you have a viscous fan then it might be time to replace it... First see what the temps are when its hot

G Man

The tanks can be removed if you are careful with the tabs that hold them on. I have read posts here on the topic, but have never done this myself at home. When reinstalling the tanks it is probably better to have it done at a radiator shop that has the clamping jig to hold the tanks tight against the gasket while crimping the tabs back over the tank flange. There are flat rubber gaskets under the tank also that should probably be replaced if you take off the tank. Not sure how these hold up to being reused. As far as testing the operation of the fan clutch viscosity I am not sure of the "correct" procedure. I used to work at a radiator shop years ago and the boss used to check fan clutches by putting the palm of his hand against the fan blades while the engine was running. If the fan would easily stop, the clutch was bad. If the fan would not stop or had a heavy resistance we called the clutch good. I know it sounds crazy, but once you have done it a couple of times it is not that bad. Just make sure you don't put your hand on the incoming direction of the fan blade.

Bill Ball

If you decide to remove the sidetank, let the shop do it. They have the right tools and technique so the tabs will be preserved and the tank resealed properly - order the seal from JimB.