Roadrunner38

Gentlemen, I need help.

1995 Honda Accord sedan with VTEC, which I think is the F22B. Hood stickers also note SHN2/SVJGFEA as engine info. Car has an auto tranny if that matters.

Problem started with mild overheating according to the gauge. Checked fluids and found some oil in coolant. In extreme cases, I've seen coolant turned to 'chocolate milkshake' consistency, but this was early, so it looked more like Creme de Menthe with the greenish cast of the Prestone.

That was about three months ago and I and an experienced mechanic friend are completely baffled why the car keeps doing this because we have replaced:
* head gasket
* water pump (and threw a new timing belt in there for good measure)
* Checked head for cracks, it was okay
* New radiator hoses
* New radiator
* New radiator fans (the left one, anyway, right one works fine)
* TWO new thermostats

My mechanic buddy, who has about 25 years experience as a professional and has just about every certification available, did almost all the work, so I know it was done right.

Here's what happens. When the car is returned to us, it runs great. Oil is clear and coolant is clear (cooling system has been flushed twice now and new coolant added). For a couple days, the car runs fine and temp gauge stays below half. Then you notice it's AT half. Then above half. Then, oh s**t, not again! When the car cools, a check of oil reveals clean oil, somewhat lower on the dipstick than it normally is (indicating it's going somewhere). And the coolant looks like it has oil getting in.

This last time, I got home from town with the gauge at about 3/4. Turned car off, opened hood to make sure all looked okay. Fan was running as normal when the car is hot and recently shut off. Looked and looked for maybe 1-2 minutes, then turned away and literally about 5 second later - BOOM! The top radiator hose blew. Wow it was loud. Plus it blew hot coolant all over not only my car but the cars parked on either side. If I'd have had my face in there, I might have had to learn braille. It was scary.

Anyway, so now the car is sitting out there with the hood up, half-dried coolant all over the place and a radiator hose that looks like a gutted animal. The split is about 5 inches long along the top and the coolant that's collected in the broken hose is just saturated in oil.

Anyone have any idea if these motors 'leak' oil into the coolant anywhere else than the head, head gasket or block? No, I haven't checked the block and I realize that's a possibility, but the engine never actually overheated and it's hard to imagine a block will just crack for no reason. Other than this problem, the car has always run well with few problems and very little oil use.

Thanks in advance for any help, suggestions or opinions.

poorman212

Help me understand "when the car is returned" and "this last time. What is going on these times? What do the tests show (comp test on all cyl). Oil in the coolant coming back after a head gasket replacement, was the head re-built, who/how was it checked for cracks?

holmesnmanny

Sound kinda stupid saying this, but, bad radiator cap? Also, does the fan work when the car is on?

Roadrunner38

"When the car is returned" means when I get it back from the mechanic friend, who does work for me out of his house (so I pay him, not the shop he normally works for). He said compression test showed all cylinders even. The head was NOT pressure tested, however it was checked for warpage and didn't have any. He said everything looked straight and clean on the block, so we — okay, he — put a new head gasket in and buttoned everything up.

As far as the radiator cap, fans — it is a new radiator with a new cap. One of the fans is brand new and they both come on when they should.

I have been cruising the internet trying to find out more about this problem. Found some of the best info right here on Honda-Tech from a few years ago. Apparently, some of the older VTEC motors were known for something called "porosity leaking" or something like that. Essentially, these were voids left during the block casting that — I don't know — just somehow start leaking oil into the water passages.

I'm going to bring the car to my mechanic again. He's going to pull the head off again and this time have it pressure tested. If it fails that, obviously the head was the culprit. If it passes, then it's the block and I'm looking at the option of spending more than the car is worth for a rebuild, or more probably a JDM replacement engine.

GarysAuto

Internally cracked head perhaps?

sweetshar73

I had an 96 Acura legend with the same problem, a dealer replaced the motor with a used one and all coolant parts and still the same problem...i sold the car..too much money and time to find the problem...It had never overheated or had any other symptom of a head gasket, my best friend is a mechanic and it baffled him.

joe_accord23

if it isnt a cracked head, then it has to be internally in the engine. It could be a cracked water jacket that causes oil to mix with the coolant while it makes it way through the oil passages.

MAD_MIKE

Sounds like the cooling system is being pressurized by combustion gases.

Were there any signs of leakage with the head gasket? Improperly torqued head bolts may have their yield strength surpassed. Were new head bolts used? A warped head or block deck will cause head gasket failure as well. Minute cracks and fractures attribute to the leakage from casting porosity issues or from prior overheating causing cracks.

b18cKoupe

I agree, for the hose to burst like that the cooling system is likely being pressureized,compression is getting into the cooling system.