: Oil cooler line leak, 4.6 N*



mtflight
04-04-05, 12:43 PM
Hello,

What is the procedure to replace/correct this problem? (oil drain?, can I "build" a gasket with a high-temperature silicone sealant/gasket maker?)

I found the leak to start right at the seal between the metal-end and the hose, as illustrated on the picture attached. The hose/line is moist with dust giving it an oily-breaded look (so it's not sopping wet but I do leave a drop or more per day--perhaps more of the lines are leaking but I could only see this one from the top).

The metal sleeve at the end of the line where it attaches to the cooler looks very crudely made--like pinched metal against the rubber hose (no wonder it's leaking!).

I'm not sure about the other lines, since all I saw was through the passenger side, where the lines attach to the radiator/cooler. I will get a ramp soon, and look at the problem from the underside. Unfortunately I live in an apartment complex with very small parking spots so I still have to find somewhere to put it on ramps.

I appreciate your help!

Regards,

Alex


Background:
I knew there was a leak from the oil cooler, as per the pre-purchase inspection at a AAA member facility--said it wasn't serious, but quoted $300 for replacing lines.

I was unsure about the exact location, until yesterday when late at night I decided to use a flashlight to inspect the engine.

BeelzeBob
04-04-05, 01:00 PM
The rubber hose is installed over the metal line end and the sleeve you described is crimped onto the rubber hose to retain it...much the way you would install a hose clamp. As the lines age and the elastomer gets harder and stiffer and less resilient there can be some leakage at the joint. The marks you see are the crimp marks from "shrinking" the sleeve into place by crimping it.

The best course of action is to replace that line with the OEM pre-made line.

You might be successful in stripping the crimped sleeve off, cutting the hose slightly shorter, reinstalling it over the tube end and installing clamps to re-make the joint. I have seen it done and if you are carefull it should work but the replacement line is a sure bet.

Are you sure that the crimped connection is leaking...??? Usually the thing that leaks is the connection at the nut. There is a small o-ring around the end of the tube that actually makes the seal at the joint and if that o-ring is starting to age it could leak and seep oil that would run down the pipe to the larger diameter crimped hose joint that would tend to exacerbate the leak due to the oil collecting there. You can check it easily by unscrewing the nut, pulling the tube out of the joint and looking at the condition of the o-ring on the end of the tube. I would check that first before replacing the hose assembly.

eldorado1
04-04-05, 04:16 PM
If necessary, you can replace the line with a hardbent "U" line, used on the 'oil cooler delete' option for a 94 eldorado (not sure about other years). Ask for the oil cooler line on it, with the 8th VIN a Y.

mtflight
04-05-05, 10:35 AM
Are you sure that the crimped connection is leaking...??? Usually the thing that leaks is the connection at the nut. There is a small o-ring around the end of the tube that actually makes the seal at the joint and if that o-ring is starting to age it could leak and seep oil that would run down the pipe to the larger diameter crimped hose joint that would tend to exacerbate the leak due to the oil collecting there. You can check it easily by unscrewing the nut, pulling the tube out of the joint and looking at the condition of the o-ring on the end of the tube. I would check that first before replacing the hose assembly.

Thanks, I really appreciate the response.
If you're referring to the metal tube, where it attaches to the radiator--the metal part is dry. the line is "moist/wet" from about 1/4inch above the crimped hose (bizarre that it's wet ever so slightly upward of where I observe the leak) and as far as I can see the hose from the engine bay, passenger side.


Thanks,

Alex


This is the first car I get "personal" with, doing repairs and maintenance myself. Do I need to drain the oil for this repair? how do I avoid making a mess? I have an Autozone a few blocks from my apartment--I'll ask them these questions unless someone wants to pitch in.

I'm going to purchase some ramps so that I can look at this thing from the underside. I'm also going to Autozone to see if they can tell me what tools I need for this job and hopefully I have some of them already.

mtflight
04-05-05, 10:39 AM
If necessary, you can replace the line with a hardbent "U" line, used on the 'oil cooler delete' option for a 94 eldorado (not sure about other years). Ask for the oil cooler line on it, with the 8th VIN a Y.

LOL I'm a complete rookie, and so i did not understand what you meant by ordering a U line on the "cooler delete" for the 94 eldo. LOL sorry.

I'm excited about correcting this leak!

Thanks,

Alex

eldorado1
04-05-05, 12:28 PM
Ahh, this must've been what the bounced PM was about (fixed that btw). Basically, if you can't figure out a way to fix it, as a last resort, you can just get rid of the oil cooler entirely. GM made a oil cooler line that just went from the "IN" port to the "out" port, with no cooler inbetween. It cost $29 or so, IIRC. I'd definately recommend you try to fix it first though, especially if you run regular oil, do any towing, or racing.

mtflight
04-05-05, 01:03 PM
Ahh, this must've been what the bounced PM was about (fixed that btw). Basically, if you can't figure out a way to fix it, as a last resort, you can just get rid of the oil cooler entirely. GM made a oil cooler line that just went from the "IN" port to the "out" port, with no cooler inbetween. It cost $29 or so, IIRC. I'd definately recommend you try to fix it first though, especially if you run regular oil, do any towing, or racing.

I don't tow, I'm switching back to regular oil, and I don't race--unless an ocasional WOT is considered racing.

So when I unplug these lines... will oil start pouring out? Or because the engine is off, oil pressure will be nil, and this should not be an issue?

I don't have a place to work on it, but I'm thinking of getting some ramps and going behind Autozone, where I've seen a few folks ocasionally stop to work on their cars. I'll buy some supplies from them so they don't complain, lol. Newspapers, and an oil drip pan are part of my supplies.

Thanks for any help and advice!

Alex

eldorado1
04-05-05, 03:57 PM
I think you'd probably be fine if you stuck with synthetic oil, like mobil 1 or similar. Will the oil pour out? I don't know, I guess it depends on how much oil the cooler is holding. I don't think it would drain more than a cup though, and possibly none at all. I'd be prepared for the cup though ;)

Just wait an hour after you last ran the engine, and you should be in good shape. Overnight would be better, but it might not make any difference. I think out Autozone has a "don't work on your cars here" sign out front, but for something simple and quick like this, you would probably sneak by. Good luck,

mtflight
04-05-05, 04:14 PM
I think you'd probably be fine if you stuck with synthetic oil, like mobil 1 or similar. Will the oil pour out? I don't know, I guess it depends on how much oil the cooler is holding. I don't think it would drain more than a cup though, and possibly none at all. I'd be prepared for the cup though ;)

Just wait an hour after you last ran the engine, and you should be in good shape. Overnight would be better, but it might not make any difference. I think out Autozone has a "don't work on your cars here" sign out front, but for something simple and quick like this, you would probably sneak by. Good luck,

Thanks, I appreciate the input! I double looked at that line, and it is leaking from where the metal connects to the hose (where it's crimped). I had an Autozone guy (older gent) look at it during my lunch break to make sure I wasn't imagining things. He also said, if I parked out in the back noone would probably bother me. So I'm buying some ramps after work, to make sure I don't have a leak in any of the other lines.

The leak is very minor, he even said to just clean it up and see how badly it is seeping out--it didn't look serious at all he said. Another alternative, if it's just "barely seeping out" would be to clean it up, then put some high temperature sealant around the crimped area. I do ocasionally see a drop and the hose is always moist with oil--so that probably won't work.


Thanks again, and if you think of anything else, keep the suggestions coming! My only other experience was the throttle body cleaning--which went smoothly thanks to the forum info and and Ranger's advice.

Regards,

Alex

BeelzeBob
04-05-05, 05:04 PM
Well..if you take the oil cooler line loose there won't be any residual pressure in it but it will be full of oil so some will dribble out but it won't be under any pressure or anything.

If it is the hose crimp leaking I would look into replacing the line or trying to re-terminate the hose onto the metal line with clamps as the hose could be splitting from old age and starting to leak at the joint...i..e....keep messing with it and it may turn into a catostrophic blowout.

Forget goobing sealant or tape or anything over the joint. It is a waste of time as nothing will hold that joint on the outside like that.

Keep in mind that once that line comes apart you cannot drive the car until it is put back together.... Not the sort of job that I would launch into behind AutoZone.....

If you do want to eliminate the oil cooler it is really no big deal. You do not need to switch to synthetic oil or anything. Just get the "U pipe" mentioned and take the oil cooler lines loose at the oil filter adapter and connect up the U tube to bypass the cooler. Later model Northstars do not have the cooler and it is not needed if you don't do any trailer towing or anything like that. Conventional oil will function fine even without the cooler. Oils available today are much better than 10 years ago when the cooler was fitted to that car to keep oil temps in line.

mtflight
04-06-05, 10:54 AM
If it is the hose crimp leaking I would look into replacing the line or trying to re-terminate the hose onto the metal line with clamps as the hose could be splitting from old age and starting to leak at the joint...i..e....keep messing with it and it may turn into a catostrophic blowout.

If you do want to eliminate the oil cooler it is really no big deal. You do not need to switch to synthetic oil or anything. Just get the "U pipe" mentioned and take the oil cooler lines loose at the oil filter adapter and connect up the U tube to bypass the cooler. Later model Northstars do not have the cooler and it is not needed if you don't do any trailer towing or anything like that. Conventional oil will function fine even without the cooler. Oils available today are much better than 10 years ago when the cooler was fitted to that car to keep oil temps in line.

The oil can withstand the higher temperatures--will the fans compensate to keep the engine cooler? I have new Dex-cool and Bars powder, thanks to your advice. (Also read the article on the new Northstar design on the May HotRod mag--nice).

I put the car up on ramps, and did notice plenty of oil all over the bottom passenger side. Three drops of oil dropped (one on my forehead) during my 20 or so minutes examining the situation. I like the idea of cooler oil--especially since I do 600 mile round trips (total) once per month. But I'm thinking access may be awkward for the procedure--so the U pipe may work best for my abilities. I assume the U pike is cheaper and easier than to replace the oil filter adapter to the version without the cooler. What would I do with the oil cooler lines after I unplug them? neatly tie them somewhere?

Thank you much!

Alex

BeelzeBob
04-07-05, 03:15 PM
The fans do not need to compensate or anything. The oil would run a few degrees hotter without the cooler but it is not an issue. The oil cooler is there for the worst case situations of driving up long steep hills in Death Valley in the summer...or towing trailers up those hills in the summer. Driving on the freeway to work each day or taking long highway trips does not get the oil hot at all and the car is perfectly fine without an oil cooler.

mtflight
04-17-05, 04:53 AM
Successful replacement of the leaky oil cooler line. I cleaned the bottom of the car and replaced the line--thank you for all your help!

Ranger
04-17-05, 09:12 PM
Alex,
First the blower motor, then the TB cleaning and now the oil cooler line. We're gonna make a mechanic out of you yet. It's a nice sense of accomplishment, isn't it?

mtflight
04-17-05, 10:16 PM
Sure is, thanks for the support! I also replaced the missing bushing in the steering/suspension... I think steering feels better (hard to imagine an improvement)--and haven't felt the rare "clunk."

There is still some kind of oil leak... after cleaning the bottom of the engine I found that the drop comes from the center engine mount... I can't see the source. It may be the gasket on the oil filter adapter, hopefully. The oil shows up on the passenger side so "geographically" it is probably the oil filter adapter, or right above it. The is wetness on the bolts around the oil pan, so perhaps they were tighened at some point--breaking the seal. There does not appear to be wetness above the oil pan, so it could be that seal too, but odd how it's only on the right side--I would bet on the oil filter adapter, as I read on one of Bbobinsky's posts. I hope I'm right. It was a little dishartening to still have oil there... although the cooler line was definitely leaky, and now at least the new one is dry.

Thanks, wish me luck!

Alex

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