Catera coolant leak

[guardian]

Originally Posted by german_catera_fan

hi there,
the purpose of the heat exchanger is to heat up the engine oil faster by supporting the heating process with hot coolant.
that way the oil get hot a lot faster than in a regular engine.
that is a great idea cuz the faster the oil becomes hot the less the engine wears out.
sideeffect is that the oil doesnt become a lot hotter than the desired oiltemp.
cuz the coolant keeps it at a certain level.
hope my english wasnt too bad.

Understood

From an engineering perspective, we live in a world of tradeoffs. Years ago rapid oil warmup doubtless enhanced oil lubricity and engine lubrication. This was good. It is what we got in the tradeoff for a heat exchanger which can, at times, become problematic.

That was then and this is now.

Today we live in a world of highly engineered, sophisticated, multigrade oils. These exhibit excellent lubricity over a far wider temperature range than oils of old.

Also, many regions of the USA do not experience seriously cold weather regardless the season.

My personal view:

Today use of a heat exchanger carries more downside potential than upside benefit.

I agree with the course taken by other posters here who deep sixed their heat exchanger in favor of an aftermarket oil cooler.

Also for USA Catera owners living in warm or hot regions of our country:

An aftermarket oil cooler, as contrasted with use of the heat exchanger, moves oil heat directly to air. This has the effect of increasing your cooling system capacity. It is akin to fitting a stouter radiator. And it is smart. Here is why:

The Catera can be intolerant of overheating. It has aluminum heads resting atop a cast iron block. These metals have significantly differing coefficients of expansion which can cause trouble out at the edge of the envelope. Especially for owners operating in warmer climates, it is wise to add to your cooling system capacity cushion.

A badly overheated Catera all too often becomes a dead Cat.

JMHO, of course.

[german_catera_fan]

i can see that. and i agree to your oppinion.
i simply forgot that its warmer in the US. as where here we can really use the heat exchanger.

[Hucgreen]

I have recently run into the a problem where my Radiator Fan, is running all the time until it kills my battier. The been disconnecting my battier unitl I can take it into a shop. of coarse its a 2001 with a coolent light that came on a couple of month after I purchased the car. I love the Catera it just seems to have so many problems with the electrical system and being too hot. Any way, My alwasy on fan, is killing my battier, I think it must be a sensor or something. anyone have any Ideas.

Michael

[zealious]

I have a pretty bad coolant leak at the bottom of the engine. I think its leaking oil in the same area. I had it almos over heat once because i had no coolant. coolant keeps disapearing errr. Where is the water valve located?

[zealious]

Here is a picture. It wasnt leaking as strong but u can see a little.. looks like the leak is coming from that hose and then sprying up and back while driving. what is that hose for?

[zealious]

more pics.
http://i4.photobucket.com/albums/y11...rl08/leak2.jpg
http://i4.photobucket.com/albums/y11...rl08/leak3.jpg
It actualy looks like its coming from higher up now.. any help would be greatly apreciated.

the second one shows how bad the leak is (pic taken about 20 min after runing the engine and shutting off. I havent spoted oil yet. its mostly water and coolant by the looks.

[zealious]

Heater cross flow valve seems to be where the leak is coming from. Anyone know the part number?

[R-Caddy]

mine started leaking, AGAIN, a couple weeks ago. Last summer it was heater control valve. This time it's the head gaskets. Local shop wants $1200 just for labor! Found a GM mechanic that will do it for $700 incl. parts. Waddaya think?

[guardian]

Originally Posted by R-Caddy

mine started leaking, AGAIN, a couple weeks ago. Last summer it was heater control valve. This time it's the head gaskets. Local shop wants $1200 just for labor! Found a GM mechanic that will do it for $700 incl. parts. Waddaya think?

These problems are routine Cat problems. You gotta tell us how many MILES are on your car!!

It's a lot of money. If you have high miles it might be time to sell her, take that money and the seven hundred, and go buy a newer Cat; a 2000 or 2001 if you can find one.

If your Cat is a low mileage cream puff, spend the seven hundred for sure.

[normalicy]

Originally Posted by zealious

Heater cross flow valve seems to be where the leak is coming from. Anyone know the part number?

It's officially called the "Heater Control Valve" & GM Part# 90566947

I just changed mine from what I've heard the hard way (removed the upper intake). I heard that you can take out the wiper blades & remove the cowl cover per this http://www.cadillacforums.com/forums/169213-post1.html

[whereditgo]

Hello,

I am new to the forum and I am looking for some info/advice. I have a 98 Cat with 75K miles. I have a coolant leak, and I am in the processes of diagnosing the leak. I did take it to the dealer and they said it was the head gasket $$$.

I removed cowl and wiper motor HCV does not appear to be leaking. Next I would like to confirm it is not the Oil Cooler (heat exchanger), prior to dismantling the intake.

The leak appears to be coming from the drivers side near the exhaust manifold. It is difficult to spot the actual origin. I have used a mirror to inspect from the bottom. Anyway to easily tell if the source is the head gasket or oil cooler?

Thanks in advance...

[normalicy]

From what I know, the coolent only leaks into the oil when it's the cooler. In my opinion, it's not too hard to reseal just in case (probably should, because it's notorious). Have you tried leaving the cowl & wiper motor off & just driving around for 10 minutes & then checking to see if the leak is more visible?

[whereditgo]

That's exactly what I did prior to taking the photo. I did find a thread that mentioned air bubbles in the overflow tank is a sign of damaged head gasket (air entering system). Unfortunately I do see small air bubbles entering the overflow tank.

Has anyone tried using "stop leak or miracle cure products", or would I be doomed to replace the gasket?

It is difficult to see exactly the leaks origin (tight space).

http://www.cadillacforums.com/forums...ht=air+bubbles (coolant/water leak)

[Marks DTM Calib]

The headgaskets dont fail and cause water leaks on these power plants.

In the very rare occasison they do fail (normaly following infrequent coolant changes causing rotting of the head gasket composite material) it results in water in the cylidners and NOT being elaked from the block.

As said before....the favourites are:

1) Heater bypass valve
2) Thermostat to block seal
3) Oil cooler plate to block seal
4) Coolant brdge seals

and in very rare cases

5) Coolant pipe to rear of block seal

Numbers 2-5 will result in water around the bellhousing as they are in or around the valley area of the block....

[whereditgo]

Looks like we have a winner behind door number 2 (Thermostat). I am enjoying a CAT that doesn't leak and a well deserved ice cold beer.

The job is not that bad, could probably do again in about 1/2 to 1/3 the time. The integrated thermostat/housing on the CAT is located on the top forward part of the block, just in front of the oil cooler, under the plenum and injectors (I remember these being in plain view and two separate parts, housing and thermostat, things have come a long way since my 69 Chevy). The most difficult part I found was removing the aluminum tube that passes thru the head and connects the thermostat/housing to the upper radiator hose.

The removal/installation of the hidden bolt that secures the aluminum tube to the block was the most challenging part of the job (no space, and working blind). I used a star socket and a thin breaker bar to free the bolt, then used a small 10mm box wrench to extract once it was freed. This bolt secures the dipstick, aluminum tube bracket and another metal/plastic bracket to the block. I would hate to strip either the bolt or the threads, as I could not imagine having to repair it.

I found in twisting the tube (as mentioned in other posts) counter-clockwise, the bracket wedges against the block and frees it from the thermostat housing. The thermostat housing and aluminum tube are held together by two "O" rings seated on the tube.

Also mentioned in other post, I did get the thermostat and "O" rings from the dealer. The thermostat/housing is slightly different then the original thermostat/housing. I was able to remove the old one without removing the lower portion of the injectors (spacer), but needed to remove it to install the new one. Also, the two bolts that secure the thermostat needed to be about 1/2" longer. I applied a small amount of anti-freeze to the seal on the thermostat and two "O" rings prior to installation, rather then oil.

I have attached some photos of the new and old thermostat housing and connector tube. Notice the gasket on the old thermostat is non-existent, as well as the thickness of the bolt holes between new and old. The other photos are of the aluminum tube/bracket.

I would like to thank you for your help...

Thanks