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77K views 78 replies 36 participants last post by  normalicy 
#1 ·
I heard someone talking about coolant leaking from a Catera at the rear of the engine but the water valve had already been replaced. I thought it didn't belong where I saw it so I thought I'd talk about it here.

On the top of the engine, in what would usually be a "valley" they installed a metal plate. This plate has sealer around the edges and bolts to the engine block but in it is mounted the oil cooler. Below the plate is coolant flowing through the engine to remove heat from the engine oil. Why they mounted this thing under the intake I'll never know, but needless to say if you have a pretty good coolant leak from this area it's likely this plate leaking.

You have to remove the upper and lower intakes and move some pipes, remove some banjo bolts and take off the coolant crossover in the back.
I have only done it a couple times so I'll post the images I think might help but this job is not for the timid. It could take you an entire day and if you mess up, you'll have to do it all over again, I'd advise finding someone who can work on this with some degree of skill.

Here are some images.
 

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#55 ·
anyone know where I can get a cheap ext. oil cooler for mine?

01 catera, been down going on 3 weeks, I've broke 3 of the oil banjo bolts
trying to keep it from leaking, I did repair the coolant leak(oil cooler plate)
I've hacked the lines, just need a cheap oil cooler.

The one's around here are $60 up to like $200+


thanks.
 
#56 ·
My 2000 Cat is leaking from this area, but when I tore it down to reseal the coolant plate I found a different problem. My leak is at the coolant banjo bolts that feed the heat exchanger. The rubber/metal washer/gaskets on the banjo bolts were blown. I couldn't find any similar ones that would fit so I used copper washers. Still leaking. Does anyone know where I can find these seals?

Thanks for all the help everyone here has been! I'm pretty good mechanically, but without diagnostic help from this site I would have parted with my Cat long ago.
 
#58 ·
I had my heater control valve changed about 2 years ago. The the car started leaking cooland slowly sometime last year again. One shop told me it was the head gaskets- probably both. I doubted. The strange thing is that it only leaks when the thermostat seems to open. I was told by a friend of mine that if it was the head gaskets the problem would have progressed, but it hasn't. I know I will need valve cover gaskets soon. Can it be the heater control valve again?
 
#60 ·
I have bypassed the bypass, i was tired of replacing that part.

3 in 2 years at $90 each sucked.

here is what i did.

I used a 3/4 to 3/4 hose connector to connect the hose from the coolant bridge( the single hose on right) to the heater core feed line (the lower hose on left, also the one the runs up front under the coolant reservoir) then I used a 3/4 hose to 1/2 npt connector in the top hose on left.

I used teflon tape and a 1/2 flare cap to seal that one tight.

Took about 30mins I've ran it for awhile and not one leak so far, and i have heat when i want it.

Cost me $9 for the parts.
 
#62 ·
I removed the HCV today. It seems ok, but my Cat started pouring coolant yesterday. Is it still possible that it's the HCV's fault? Where could it be leaking from? I need to get this car back on the road. Also, is it OK to just get a T-connector to connect the hoses, instead of using the alve again? Or could it be some other reason for it?
Thanks
 
#63 ·
The 3 lines are for 2 paths, It took me awhile to find how it worked and flowed.
the valve is vacume controled to let it flow from the right(feed line) to one of the 2 other lines.
top left (into heater) or bottom left (into bypass feed)

Only way i can explaine it, top left goes into heater then out to radiator, the bottom left goes into the flow after the heater but going to the same place. SO if a vacume is applied you have hot water in the heater core, no vacume no heat as the flow is bypassing the heater core.
I was without heat for a year or so because the vacume line from inside the car to the HCV didn't work, I T-'ed off a line from the intake and ran to the HCV so i could have heat. and after replacing the HCv 3 times in 2 years, i got sick of paying $90 a pop for it.
 
#65 ·
I took my Cat to dealer for what I thought was going to be a HCV replacement. Small leak, could smell coolant. They call me after 2 hrs, seems that some "bridge" is leaking and is going to cost $800 to fix. But thankfully I can afford it.
I found $25K hidden in the trunk. :thumbsup:
 
#67 ·
When checking into a leak that is located on the driver side on the Catera there is usually a few things to look for.
Is the leak dripping from the manifold? If it is, then it will probably end up being the Head Gasket.
But before assuming the worst check out the obvious first.
Look for a leak in the HCV, Coolant Return Pipe, Oil Cooler Cover, Water Crossover or even the thermostat.
I just completed a complete head job on my Catera and it was the head gasket that caused the mystery leak coming from the Driver Manifold.
One thing that should be noted, The factory engine coolant is the red type and that type is highly corrosive. When changing over the head gasket or doing a complete Flush then change to the Green coolant. I can show the damage on my head gaskets that where eaten away because of the coolant. The head was not damaged but you could clearly see where the coolant ate into the gasket and eventually worked its way out into a leak.
I will post some picture if you would like just email me
bait@livebaitandtackle.com
Thanks Keith
www.livebaitandtackle.com
 
#70 ·
Re: Catera coolant leak - Why Me lol

So, My poor baby went into the dealership today with a nasty coolant leak.
I brought it into a few other places, but none of them wanted to work on the car because they didn't have the proper tools. So I guess I'm stuck bringing it to the dealership.

1998 Catera with 145,000km.

Prior to this, I've had no major problems, but have only had the car for about 2 years.

I did a run on the vin # and I found that it was diagnosed with a minor coolant leak just before I got the car. In the report I received, it mentioned the leak coming from one of the heads or the oil cooler.

I'm the lucky one who got stuck with it when the coolant leak got really bad. :thepan:

I do notice that its leaking from the back of the engine though.
So I'm kind of hoping its the HCV.

Can anyone suggest a reasonable price that it should cost to get this repaired.
I will post the quote I get from the dealership as soon as it is available.

-Jon
 
#75 ·
On the top of the engine, in what would usually be a "valley" they installed a metal plate. This plate has sealer around the edges and bolts to the engine block but in it is mounted the oil cooler. Below the plate is coolant flowing through the engine to remove heat from the engine oil. Why they mounted this thing under the intake I'll never know, but needless to say if you have a pretty good coolant leak from this area it's likely this plate leaking.
:yup: exactly what was wrong with ours!! lol, but we thought freeze plugs were the culprit, so took the entire engine out!

does anyone happen to have the part # for this gasket? none of the retail parts stores seem to have it, or we didn't give them the correct name for it...whichever...:annoyed:
 
#76 ·
ok i'm at work so i don't have luxury of reading ALL of the posts, although i have read first 3 pages.. if i'm lucky enough to get seen, i need help or pointed in the right direction.
i have a 1997 Catera w/ 94k miles. the cooling has been giving me a problem that stop leak isn't helping anymore, so i swapped out the radiator that had a clear crack in it.
i was unfortunate and uneducated enough to not know that you should bleed the radiator system before excitedly driving my car home when POP! hot coolant rushes into my passenger side.
and rapidly outside of my car..

what i need, is the easiest directions to access the back of the engine area, and under my passenger dash, since i have to do this myself.. i need to check if its a hose or the core itself, easy fix i hope... if it werent bad enougth that i snapped connection off a $450 "smog reducer" while trying to remove a heater hose.. this is the most fragile, most expensive car i have ever worked on, i think they designed it to make DIY's fear it, so that we take it directly to the dealer.. they break the damn thing so they dont have to work on it either... but i do love this car, shame about all the problems it has.
i have no money to spare at a dealership, everything ive broke on this car has avg'd $400 dollars thank god these things are popping up regularly in the cash and carry junkyard. paid $27 ($350) bucks to get a coil pack, and $7 ($450) for the damn smog reducer.. sorry i think im having a meltdown..
 
#77 ·
i realize this thread is old, but i am hoping someone can offer insight to fixing the oil cooler/heat exchanger problem that plagues this car. I am going to give this a try myself, I have worked on cars before, and what i don't have in knowledge i make up for in determination.

1. when disconnecting the fuel lines from the rail, is disconnecting the negative battery cable enough, or is there some other relief valve i must find and deal with?
2. how likely is the repair to hold? would i be better off attempting the aftermarket cooler option linked to this repair?
3. is it necessary to replace the intake/plenum gaskets when reassembling things back together? there is no mention of this as being necessary in the step by step pdf document explaining the job.

thanks- I really hope someone can help-
 
#78 ·
You don't need to replace the O-rings on the plenum. I haven't yet and I've had them off twice. The best detailed pictures I've found at the Omega Owners Forum. The Europeans have been working on these for years, as they still sell a version of it today. Just be sure to note where the advice comes from. I made the mistake of forgetting the driver side of an English car is opposite our own. As for the oil cooler, why compound their bad design by re-installing it? An aftermarket remote mounted unit has to be a smarter alternative. I always use Mobil 1, so the temp factor is mollified. I'm just concerned as to how you would close the coolant openings after the change. Has anyone done this? My car has 76k on it, and although my cooler is sound, I have to anticipate the repair if it fails.
 
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