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RVluvin · 06-06-2012, 07:19 PM

The radiator overflowed on the 8.1 Chevy in my 09 Safari although the engine was not overheated according to the temp gage. The radiator coolant flowed like oil out of the coolent overflow resivor and felt very greasy. After the engine cooled, I suction out fluid from the radiator and it defintley has oil. Neither the crankcase or the tranny have water. I called a nearby repair shop, and found out that not only do I need a new radiator, but all hoses need to be replaced due to the oil in the coolent. Is this true?

I can replace a radiator on just about any vehicle, not certain about tackling this job. Repair shop charges $65 labor per hr. I have no idea how much time this job would call for. Has anyone removed the radiator on their motor home? I'm interested if it was fairly easy, or very dificult job.

rocknrun · 06-06-2012, 07:29 PM

How did the oil get into the coolant system?

Davdeb1 · 06-06-2012, 07:37 PM

Probably at the connections on the trans cooler. I don't believe the cooler would suck in anti freeze. This is just a guess on my part as it happened to me with a car 30 years ago.

RVluvin · 06-06-2012, 08:06 PM

The transmission cooler is incorporated within the radiator, which has been common in the automotive industry for probably the past 30 years or so with automatic transmissions. The motor home also has an motor oil cooler incorporated into the radiator as well. These inner tubs within the radiator tank are what make up the trans/motor oil cooler and one or more must be leaking within the radiator. My only quess as to why there is no oil in the crankcase or tranny is that these lines are under pressure.

I'm wondering if a radiator shop (if they still exist) can remove the tank and locate and seal the leak as opposed to purchasing a new radiator.

Anyone with expertise in this matter, your input would be appreciated.

WeatherTodd · 06-06-2012, 08:39 PM

I would pressurize the cooling system and see if you have any leaks.

My 8.1 has a seperate oil cooler for the trans so I dont see that being an issue.

You can flush the cooling system with vinegar or CLR.

PREACH1 · 06-07-2012, 02:38 AM

Yes this true oil begin to break down the rubber ( eat the hoses inside out) transmission fluid makes them swell and become soft then burst. Sounds to me the inter cooler in rad. Is leaking internally. Rec. You flush & change hoses

TXiceman · 06-07-2012, 06:16 AM

First thing is to check the transmission fluid. If milky, you have a leak in the radiator mounted cooler. This means pulling the radiator and getting it to a radiator shop for repair. When you get it back you will need to do a radiator flush and refil with clean antifreeze. Then yo will need to drain, flush and change filters on the transmission and refill.

It is a bit if work, but beats failing a tranny or engine.

RVluvin · 06-10-2012, 09:22 AM

As mentioned earlier, I currently don't have water in either the motor or tranny fluid. While I do have some oil in the in the sample of coolent I removed from the radiator, it's very little (just a think milky substance flooting on top). I'm wondering if this oil could be from just the pre-lubing in the assembly of the engine? I'm the second owner, maybe this first accidently put a little bit of oil into the radiator by mistake while changing the oil. The neck to the radiator and where the oil gets poured in are very close together. This motor home is only 3yr old, with less than 15k miles. I find it hard to believe the radiator is bad. I can understand a defect within the first few thousand miles, but not after, 14k. Iv'e decided that before I give away my money to a mechanic, I'm going to flush out the cooling system, use some cheep antifreez, install a new radiator cap, and go for a drive. Then I'll drain the system and see if I still have oil mixing in with the coolent. I'll post a followup for those who have taken an interest. Thanks!

Mike Canter · 06-10-2012, 10:16 AM

You have a blown headgasket. The reason the radiator overflowed was because the headgasket leak allowed gases to get into the cooling system and pressurize it beyond the radiator caps setting. This is a pretty common symptom and I wouldn't try and make it too hard to figure out. Stick your nose down by the exhaust pipe while it is running and see if you smell the sweet smell of antifreeze. Also how much exhaust cloud are you see coming out the exhaust pipe? The reason you don't have water in the oil is because the headgasket leak is probably in the gasket metal sealing ring around the cylinder part of the gasket and requires pressure to push the oil into the coolant and it is not a big enough leak/hole yet for the coolant to flow backwards into the cylinder. The other test you can do is to take out all the plugs and run a compression test and see if you have a low cylinder or two cadjacent cylinders both down. The problem is the leak may not be big enough to show low on a compression check.

Dogpatch · 06-10-2012, 10:25 AM

Quote:

Originally Posted by Mike Canter

You have a blown headgasket.

That would be my guess as well! Head gasket.

Midniteoyl · 06-10-2012, 10:39 AM

Quote:

Originally Posted by Mike Canter

You have a blown headgasket. The reason the radiator overflowed was because the headgasket leak allowed gases to get into the cooling system and pressurize it beyond the radiator caps setting. This is a pretty common symptom and I wouldn't try and make it too hard to figure out. Stick your nose down by the exhaust pipe while it is running and see if you smell the sweet smell of antifreeze. Also how much exhaust cloud are you see coming out the exhaust pipe? The reason you don't have water in the oil is because the headgasket leak is probably in the gasket metal sealing ring around the cylinder part of the gasket and requires pressure to push the oil into the coolant and it is not a big enough leak/hole yet for the coolant to flow backwards into the cylinder. The other test you can do is to take out all the plugs and run a compression test and see if you have a low cylinder or two cadjacent cylinders both down. The problem is the leak may not be big enough to show low on a compression check.

Craig_R · 06-10-2012, 10:50 AM

I would also agree with the blown head gasket theory. Minimum I would do is get a second opinion from another shop.

chaunclm · 06-10-2012, 10:56 AM

I agree its a head gasket, bad news for sure.

Mike Canter · 06-10-2012, 04:14 PM

It is a lot easier to fix a Chevy big block headgasket than a diesel headgasket especially on a front engine MH. A recommendation if it is getting up in miles then I would pull both heads and get the valves done and the head surfaces trued. There is no point in pulling all that instake manifold and other stuff and just replacing the one head gasket and no complete valve job unless you are going to sell it soon. You also need to have your cooling system flushed out with some heavy duty radiator cleaner to get rid of any oil deposits after you get the motor back together.