On the road again

After two weeks of work evenings and weekends, I got the car running again. The head gasket is changed. There was water in the low spots around the rocker arms when I took the valve cover off. Could not find any indication on the old head gasket as to where the water might have been leaking into the oil. Hope just changing the gasket solves the problem. A few days of driving should make it obvious if there is a different problem. There are a huge number of parts that have to come off the car to get the head off it.

Never ceases to amaze how much dirt collects on engines in place where it is difficult to clean. I guess after 23 years some is to be expected. Too bad the dirt does not have rings like trees to date various maintenance actions and driving events. But then maybe it does. One could at least do some speculation while digging the grim off the parts before assembley.

I did have surprising difficulty getting all the air out of the cooling system. Good thing I did not put new expensive antifreeze in it just on case something went wrong. Most of it went on the floor of the garage. For some reason, the air was not coming out of the vent port very well. The engine got warmed up and then burped most of the coolant out of the reservoir as I had the cap off. This went on for a few minutes. I assumed that as the air was purged I would have to add more coolant, so had the cap off. Had to add a gallon or so before the thing settled down.

Bob in Lake Havasu

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Bob in Everett
After two weeks of work evenings and weekends, I got the car running again. The head gasket is changed. There was water in the low spots around the rocker arms when I took the valve cover off. Could not find any indication on the old head gasket as to where the water might have been leaking into the oil. Hope just changing the gasket solves the problem. A few days of driving should make it obvious if there is a different problem. There are a huge number of parts that have to come off the car to get the head off it.

Never ceases to amaze how much dirt collects on engines in place where it is difficult to clean. I guess after 23 years some is to be expected. Too bad the dirt does not have rings like trees to date various maintenance actions and driving events. But then maybe it does. One could at least do some speculation while digging the grim off the parts before assembley.

I did have surprising difficulty getting all the air out of the cooling system. Good thing I did not put new expensive antifreeze in it just on case something went wrong. Most of it went on the floor of the garage. For some reason, the air was not coming out of the vent port very well. The engine got warmed up and then burped most of the coolant out of the reservoir as I had the cap off. This went on for a few minutes. I assumed that as the air was purged I would have to add more coolant, so had the cap off. Had to add a gallon or so before the thing settled down.

Bob, I hope you don't have the classic cracked head thing where coolant oozes out by the cam bearing castings and leaves coolant around the rocker arms.... Wishing you the best, Rick

Rick, is that readily observable with a pressure test?

alan

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alanrw
Rick, is that readily observable with a pressure test?

alan

Usually, yes... There was a fella here that pumped his cooling system with a low amount of air pressure (from a compressor) and he saw it weep right there. Our cars do have history of this.

Rick

The water level seems to be holding. I plan to take it for a little shake down cruise on Saturday just to make sure before I head for Montana on the Independence day weekend. No evidence of water getting into the oil.

Bob in Lake Havasu

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Bob in Everett
The water level seems to be holding. I plan to take it for a little shake down cruise on Saturday just to make sure before I head for Montana on the Independence day weekend. No evidence of water getting into the oil.

Good plan, most probably everything is fine now.

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Jose Pinto

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Bob in Everett
The water level seems to be holding. I plan to take it for a little shake down cruise on Saturday just to make sure before I head for Montana on the Independence day weekend. No evidence of water getting into the oil.

Good plan, most probably everything is fine now.

Time, and mileage will tell. Good Luck Bob, after all that work you should have a decent shot at it... Rick

Well, perhaps I am the victim of this problem. Went for the pressure cap that actually holds pressure and the next trip of about two hours total run time, lots of water lost and obvious condensation in the oil filler and breather hose. How would one recognize and / or repair this kind of crack? Is it repairable?

Bob in Lake Havasu

I would suggest it is time to pressurize the cooling system with air and see where it going.

Bob,
If it turns out the head is cracked; the only real solution is to replace it.
Welding cast aluminum is tricky at best but nearly impossible to do successfully in the convoluted shapes and recesses in the head

Finding a good donor at the wreckers shouldn't be a big problem but finding a good one may prove a little more difficult. A good rebuilder can analyze the head for cracks before wasting any time on it. That might be a quick way to find out if yours is truly cracked.

I had not considered that it might be cracked when it started leaking. Wish I had. It was a lot of work taking it off and putting it back on. There are a couple of recent suggestions I should have done, such as pressure up the coolant system with the valve cover off and look for the seepage. I suppose finding it would only confirm what I already know now is that it needs to be replaced. I had concerns that a repair shop could have a tool that would pressurize the head while off the car.
Cost containment for repairs on an engine with so many miles is a concern. Have considered an engine swap for S50/52 but have not lately seen a great candidate.

I need to do what it needs though, the car is in such nice shape it would be a shame to give it up and I like driving it so much that it is like an old friend.

Bob in Lake Havasu

I think that repair shops would do something like a dynaflux test to find any cracks. It doesn't involve pressurization. If you have access to the penetrants and dyes; you could do the test yourself. Google 'dynaflux crack check' for details.

Any places by you that sell remanufactured heads? Typically, the head cores are checked for cracks before rebuilding. Or any of the online BMW parts venders?
But do invest in pressure testing the engine before you tear it all apart again. Diagnosis is key in these situations.



Edited 1 time(s). Last edit at 07/14/2013 11:26AM by alanrw.

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Archeo-peteriX
I think that repair shops would do something like a dynaflux test to find any cracks. It doesn't involve pressurization. If you have access to the penetrants and dyes; you could do the test yourself. Google 'dynaflux crack check' for details.

Hey Bob, I'm so sorry to hear this. I was ready for good news! Peter is on the right track as usual but there might be one thing you could try before tearing down, If you have a spare radator cap, rig a fitting you can tie in to with an air line. You can use a compressor (at low pressures) or even a bike pump if there's a gauge on it because you have to keep track of how much pressure you have in the system.

Normaly the motor has to be operating temps for the crack to open (but not always, some will leak dead cold), and for you to see any coolant flow at the cam stands in the head casting, you might even have to run the motor while you're doing your pressure tests but I think it's worth a try and Hey, it's free! You can always have a rag or something over the valve gear so oil won't spray all over. You can try to keep it at a minimun anyway.

If you do need a head I agree with Peter, have it magnfluxed or some kind of crack testing done before you even waste any time... Although, if you find a reasonable motor that's holding a decent coolant level chances are, it's fine. From what I've heard and read about this head cracking issue is; if you get past 60-100k the head is fine, it's taxi tested.

Best, Rick

The "taxi" test is one reason I do not mind buying cars with 100k on them. My cabrio had 120k on it when I got it. It has been super reliable. Just the normal stuff like a fuel pump, heater core and oil leaks. Now it has 228k on it but the interior is still in great shape and the body is better than when I bought it.

I have one head found and another possiblilty to do a swap directly with cams and everything. Not sure how much to spend on having a shop work on them. Have heard it can go to $1000 to have the full treatment of valve grind and stem bushings. If I was building a race engine maybe but not just to get to work. New gasket kit coming from Pelican parts.

Bob in Lake Havasu

Now you made me feel less stupid about my MB ex-taxi with 665000km and counting... Most things were tested and replaced several times, and something is always about to give, but still they don't break all at once, so it is the ultimate ongoing project.
On the upside, the car depreciation is completely off the equation.

Some cars, like any good e30, even increase price with age.

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Bob in Everett
The "taxi" test is one reason I do not mind buying cars with 100k on them. My cabrio had 120k on it when I got it. It has been super reliable. Just the normal stuff like a fuel pump, heater core and oil leaks. Now it has 228k on it but the interior is still in great shape and the body is better than when I bought it.

I have one head found and another possiblilty to do a swap directly with cams and everything. Not sure how much to spend on having a shop work on them. Have heard it can go to $1000 to have the full treatment of valve grind and stem bushings. If I was building a race engine maybe but not just to get to work. New gasket kit coming from Pelican parts.

If you go the used head swap-over I might be able to help with things to look for. Certainly mileage is a concern as to what shape the head is in but also how it was serviced is a biggy. Since we can't know the latter I would look for signs, even banal ones like sludge in and under the valve cover.

I forgot which engine you're working on, 2.5 or 2.7?

Rick

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rkj
Normaly the motor has to be operating temps for the crack to open (but not always, some will leak dead cold), and for you to see any coolant flow at the cam stands in the head casting, you might even have to run the motor while you're doing your pressure tests but I think it's worth a try and Hey, it's free! You can always have a rag or something over the valve gear so oil won't spray all over. You can try to keep it at a minimun anyway.

Not always. At work we had a car that was massively putting out white smoke when cold and stopped when at operating temperature. There was a miniature hole in the cylinder running to the water jacket, just enough to let water in when cold and close when warm.