Catera coolant leak

[ewill3rd]

Maybe the term is not scientifically correct, but the principal is that heat is taken out of the oil and transferred to the coolant.
Seems to me that it makes the oil cooler than it was when it went in.

Most oil coolers on other cars are located in the radiator side tanks, but it's still the same principal.

As much fun as it is to argue semantics, comments like that can serve to confuse more people than it helps.
Walk into a parts store and ask for a "heat exchanger" and see what you get.
I think they call it that for the sake of convenience.

[Mike in Ohio]

I’m about to break into oil cooler next weekend on a ‘98. I have a couple of questions:

1. Do you recommend draining the oil and coolant before doing the procedure? It’s time for an oil change anyways so I figured I’d do that but didn’t want to drain the coolant unless I needed to. I imagine the best bet is to drain the coolant, do the procedure, flush, then refill if this is necessary to begin with.
2. The GM shop manual mentions you have to remove one of the catalytic converter in order to remove the feed/return lines by the oil filter – would you recommend that? Also mentions removing part of the exhaust heat shield - same question on that as well.
3. Any clue what pressure to test the cooler at for leaks? Was going to try and hydro test it myself.
4. I see several items mentioning washers/gaskets at the banjo bolts at the oil cooler itself - are there similar ones at the connection point by the oil filter that need to be replaced?

Thanks for any advice you have.

[ewill3rd]

Draining the oil isn't required, but you have to remove the cooler and the filter so it won't hurt.
Draining the coolant is more important, I'd go ahead or it's going to get everywhere.
You don't have to remove the catalyst, but you do have to reach behind the motor and loosen the bracket for the oil lines in order to reposition them, I think the fittings on the block screw in with flare nut fittings, they could be banjo bolts, I have to confess I have only done this job twice.
I try to stay away from Cateras because I don't know them as well as I do other cars.
Cooling system pressure tests should be about whatever rating is on the cap, if that's what you mean. Most caps are rated for 15 psi or 16 psi.
I don't know of any way to test the cooler itself for holding oil, I have never seen one leak oil though.

Good luck and be patient. Don't rush yourself and don't get frustrated.

[CtA318]

Just finished this job amoung many others on my 97 catera. I started her for the first time in two months today. I need to re-fill the cooling system and then Im going to drive it around for awhile to see whats what. After that I'm plaining on changing the oil.

Good luck to anyone going to do this job. It sure is a lot of work.

[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.

[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?