Not an Head Gasket Problem

Hi,
I have a E36 316i with a very strange problem.
A couple of weeks ago, after a 200Km trip the top radiator hose came off. It came out while the car was running and made a bang like it
came off due to some pressure. The temp gauge was normal. Stopped immediately and called the insurance assistance. The tow truck guy said it was a simple thing and no need to tow the car, unless I wanted to.
It just reconnected the hose, toped radiator with watter with the heating on on full hot and bled the hoses by pressing them with the hands so that the air came out. So far so good and it looked OK to me.
We let the can run for a while to check the temperature on both hoses looking for a jamed closed thermostat or something and it looked ok, hot watter on both hoses.. after about 10minutes or so the gauge temp went to 3/4 and then to red zone.
Something was not OK. He let pressure out and them removed rad cap and re-toped with watter. Maybe is was some air bubbles on the system.. dunno.
After the last refill of watter. We let the car run again a bit longer. 10-15 min.. and it looked normal.
I drove about more 30Km with the temp gauge oscillating a bit between middle and 3/4.about 10 hours later I drove back home and with the same oscillation in the temp gauge, until it suddenly - in less then a minute - went to red zone again. I just drove about 1km until the next service station right ahead.
Let it cool for a while and after removing the pressure, completely removed the rad cap. A lot of brownish watter boiled of the rad. Refilled with watter and managed to drive the last few Km home.. normally.
The next day I have the car towed to a shop just under my workplace. I immediately suspected of blown head gasket.That same diagnostic was made by the chief mechanic. Brown watter on the rad, showing signs of fat. And the oil cap also shown the typical signs of water in the oil.
I agreed to proceed to replace the head gasket and all contaminated parts of the oil and watter circuits. But... when the head was removed, no signs ruptures of leakage. The head was resurfaced slightly just to know it was not bended. The head showed some signs of corrosion so we had the head tested... but the head is OK.
Today the chief mechanic will have an expert to look at the engine block still mounted on the car.
The engine has about 170K on the clock and was always well taken care of, in an authorized dealer. Full stamped revision book.
I have no idea what to do now. Should I just take a chance, thrown in a new head gasket and see it goes OK? Anyone with a similar situation?
King Regards
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I had a similar issue on an E30 316, 1.8 l engine (1987). Mayonnaise inside the tappet cover as well as along the oil gauge. Nothing in tre radiator. It appeared that there was a very small crack in the head, just below the nut of a lug. It took weeks to see what place the water was coming from, at a very specific tempreature, not below, not above ! Even with a tracing agent, the dealer didn't manage to see anything after the first removal. The crack was closed at room temp.
I decided then to troubleshoot by myself. Everyday, back home, I removed the tappet cover to look inside and I finally suceeded but the camshaft and all the tappets had to be replaced.
I didn't have to pay anything. BMW guarantee covered everything.
Normally the visual inspection of the head gasket would reveal the location where the water was passing through. Up to you to insist in order that the head is checked. You also have to keep in mind that water in the oil isn't within the manufacturer's specs ! A repair like the one I had to face to, if not taken within a guarantee, is very costful. If performed too late, the crankshaft also, needs a replacement !
In my opinion, the fact that the security valve opened, probably denotes a pressure increase due to a big leakage. Possibly coming from a gasket. Let the experts confirm or not.
Regards

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If the head gasket is okay, the head isn't okay or the block isn't okay. But the thing is, the problem could be very small and it could be hidden.
If oil has leaked into the coolant, there is a leak somewhere and your job becomes to find it.

Have him send the head out to be magnafluxed. The block itself is hard to magnaflux, but it can be tested with a penetrant dye. However, it will need to be removed and cleaned to do this.

You can do that. If it turns out not to be okay (and I suspect it won't), you're in for a new engine. But you might be okay, and it's not a lot of labour to find out.
The alternative is to get the head and block dye-tested, magnafluxed, or pressure-tested, and then replace _only_ the head or the block as needed. With only 170k on the engine this might not be a bad thing to do either. --scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

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in article snipped-for-privacy@d32g2000yqe.googlegroups.com, HangaS at snipped-for-privacy@gmail.com wrote on 2/20/09 9:30 AM:

next time if I may suggest ... since the cooling system is involved is tow it.
The radiator system is a high performance fragil thing that requires top notch care to keep it in factory specs.
Wrapping the hose in with something from the hardware store is not proper care I would like you to consider ... tow it in, have them do the proper maintenance care (every 90K miles is a complete subsystem R&R) ... so you are past 180K miles ... by some 20K miles ... you should have had the 90K mile subsystem R&R on steroids already done.
That means new hoses, new bushings, new bearings, new wheel and transmission seals, if the engine is top notch still having factory spec compression in the pistons ... do the work and pay the bill.
If not ... then go cheaper and drive it into the ground.
You can get a LOT OF MILES out of these cars ... another 160K if you are lucky ... but you have to do the work ... and maintain factory specs I am sorry to say.
With the Radiator ... lose coolant at high way speeds, you have maybe 90 seconds if you are lucky to see the red light in time and it works ... to turn the engine off or it is foxed up beyond recognition.
Moral of the story, do not Chenny around with your radiator system.
Sort it out correctly, promptly and smartly ...
the other subsystems you can fiddle with a little.
Hope that is a help to your long term financial success.
sumbuddie peaking behind the curtain
:?
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Hi,
Thank you all for your opinions.
Unfortunately I had not very good news today. I got the confirmation that the head is OK after a pressure test. They don't do magnaflux testing but they assure the head is OK. In fact they assume the responsibility for the costs if it turns out to be the head.
As to testing the block.. well that is just to expensive in labor. Removing the crankshaft, pistons, and refit everything again with new cylinder rings.
In this scenario I also I have to balance the market value of the car even in good conditions. It does not make much sense to spend more then half that value.
I might be throwing money out, but the alternative now is to get a new used engine, which I don't know the history off.
So I'm off to rick in fitting a new head gasktet, have the cooling and oil circuits cleaned, fit new oil and coolant and add stop leak fluid hoping that this solves the problem. If not.. I had to go for a new engine anyway.
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No, that _is_ good news. It means either the problem is the gasket, in which case you're fine, or it's the block, in which case you have a problem.
There are some engines where symptoms like you describe can also be caused by bad manifold gaskets but I do not think your engine is like that at all.

Yes, this makes sense. So button the engine up, get it on the road and drive it. Either it will be fine or it won't.

If you _like_ the car, it's worth spending far more than the value of the car to keep it running. This is because you know the car, you know it has been properly taken care of, and you know everything that goes wrong with it normally. If you are happy with the car, it's worth spending money on it even if it will never be worth as much as you put into it.

That would be a good idea, IF the head gasket doesn't do the job. But first put a new head gasket in, drive it around and see what happens.

Do not use the stop leak fluid until you ABSOLUTELY are sure that the new head gasket did not fix the problem. The stop leak stuff is really only a temporary repair and in the long run it will do harm to the system.
IF you still have the problem after putting a new gasket on and buttoning the engine up, try the stop leak stuff before you replace the engine. It won't be a permanent fix, but it might be an okay temporary one. --scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

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I had a similar problem with my 528 e39 except there were no signs of oil in the water etc. Turned out to be the thermostat even though the BMW dealer ruled this out.

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Well, so you know it's not a bad head gasket.

Well, you have a couple choices.... but since you are reasonably sure the head is good (not 100% sure, but reasonably sure), there is a reasonable chance that the problem is in the block itself.
The solution I would look into would be to just drop a junkyard engine into the car. Look for an engine from a car that was wrecked with fairly low mileage on it.
For a lot of cars, I would strongly recommend against junkyard engines because you don't know where they have been and you don't know what problems you are buying along with them. But the engine on this car is pretty solid and I don't think I would hesitate.

This sounds like a leaking oil intercooler. There was some E36 option with an intercooler... I don't know the details, but I would check if I were you. It should be an easy thing to remove for diagnosis if you have one. --scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

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