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white smoke...passing beyond denial

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My 1975 has been sitting around for the past couple of months.  Before I started, I noticed the radiator reservoir tank was almost completely empty, much lower than it had been a couple of months ago.  After I started the car, I got lots of white smoke:

White_Smoke_BMW.thumb.jpg.bb7e1c71f13ea8c43413afd355ba8400.jpg

 

The car has had a noticeable issue with coolant level dropping for over a year, but I rationalized that this was due to trapped air being displaced from the last coolant change.  A few months ago, I had removed the plugs to see if any of them had the "steam cleaned" appearance that has been described as a hallmark of a coolant leak.  They didn't really show signs of that to my untrained eye, so I assumed everything was hunky dory:

Group_Shot_BMW_SparkPlugs.jpg.27b9bf937ebd616f75bbe2fdab6e7c5d.jpg

 

Pretty sure now that I'm going down the road of head gasket replacement or trying to find failures in the head or block.

 

My first set (oh yeah, I know there will be more...) of questions are:

 

(1) I've seen advice on prior threads to do a compression test or pressurize the radiator and then remove plugs to look for moisture as confirmation tests that there really is a coolant leak into the combustion chamber(s).  But, really, with the white smoke and dramatic drop in coolant level, it seems unlikely to be something else.  Is there additional diagnostic value in doing these tests to try to pin down the location of possible failures in the head or block?  Or do the tests just remove the 1% of doubt that there is a coolant problem?  Or maybe measuring compression before any gasket replacement to establish the problem and then seeing it fixed after a gasket replacement to confirm the fix is the point.  Should I invest the time on more diagnostics?

 

(2) Can you recommend a compression tester that works well on the 2002?

 

(3) I won't be able to work on this for a month due to upcoming travel.  Do I need to take pains to drive out any accumulated coolant from the cylinders to reduce the risk of rust?  Is the best way to do this to leave the radiator cap off (to prevent pressurization) and run the car for a couple of minutes to burn off the coolant?

 

(4) Is there any chance that tightening the head bolts to further compress the gasket might fix the problem?  I have never checked how tight they are.

 

(5) If I have to suck it up and replace the head gasket, is there a detailed written procedure on how to do this?

 

(6) If I replace the head gasket, will this trigger a valve adjustment (another skill not currently in my bag of tricks)?  Any other adjustments?

 

(7) Are there different types/grades of head gaskets?  Certain types to avoid?  Best place to buy?

 

Thanks for your thoughts,

 

Terry

 

 

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(edited)

Not sure where you are located but the other day when i was cold my car put out a bunch of steam when I fired it up.

 

 Oh, I see the CA plates. Still could just be a cold start.

 

 

Edited by 7502

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When in doubt-bore it out! 

 

You can go to your local pine tree air freshener and oli change parts store and buy a DIY at home radiator test kit to see if you have exhaust gases mixing with your coolant.  But given that you are losing coolant and producing steam out the pipe, it's highly likely burning water in the combustion chambers.  

 

That being said. 

 

One of three things is most likely going on in order of oh shit factor. 

1) Bad head gasket

2) cracked or corroded head passages

3) cracked block  

 

At this point you could try and torque check the head to 52lbs, but unless some idiot built the motor and never did the final torque sequence, not gonna do much for you.  

 

Removing and reinstalling the head is fairly straight forward and can be done in an afternoon for the novice. However, if your head is cracked you may not know from just looking at it.  If your passages are eroded away and the cause it will appear more easily with the head gasket material showing evidence of failure at the spot of the metal that has turned to chalk.  

 

At this point I will defer to others to guide you down the road of what to do given your financial means.  

 

Might be time for that eruo spec high comp build plus side drafts. Blunt is selling 90mm 10:1 pistons for $500 right now. 

 

but what do I know.  

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Check all end every coolant hose that they are a) tightly clamped and b) not hardened as they may leak. Also check that water pump is not leaking (from gasket & little hole under housing). Check radiator cap gasket too. Radiator and heater core could leak also.

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And leak down test, not compression test.  Leak down test will tell you about everything.  It'll tell you between which cylinders it's leaking, exhaust valves, intake valves, rings...  Leak down test.

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I used BMW's blue coolant when I changed mine and learned that it leaves a chalky residue when it dries.  I had flipped a hose clamp over on one of the hoses and that connection had sprung a small leak, leaving traces of light blue powder wherever coolant had been.  Sort of a neat feature.810418673_002(800x600).jpg.0412ea953eb2380afe7b49b8efa00dc4.jpg

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(edited)

And unlike a regular leakdown, do it cold.  When things aren't expanded and self- sealing.

It doesn't need to be fantsy at all- just put air against each piston at TDC, and see where the water

and air come out.

 

Also, the sniffer test-

 

If that's coolant, you'll  be able to smell and taste it coming out of the tailpipe.

 

If you're worried about leaving it, and you ought to be,

pull all 4 plugs and crank it a bunch- like, 30 seconds,

wait a bit, then repeat twice more.

Then squirt quite a bit of oil (more than 70 cc) 

down a bore, roll it over by hand and let it spit the excess out,

and then repeat for the other 3 cylinders.  That'll reduce

the chance of cylinder wall and ring damage.

 

t

 

Edited by TobyB
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https://www.summitracing.com/parts/otc-5609/overview/

 

I have an older version of this one.

 

But seriously, for this level of testing, ALL you need to do is get

air pressure into the bore.  My first tester was an old spark plug

with the porcelain knocked out, and tapped for an air fitting.  The 

biggest expense was the tap.... 

 

t

 

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All of the above and / or "rent" a free coolant tester from your local big box parts store with the dye to tell if  you are getting exhaust in your coolant, indicative of one of the ways coolant can be diminished.

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I had a puzzling coolant loss on my '69 at about 157k miles--no external leaks, water pump and radiator ok, good compression in all four cylinders, wet or dry.  

 

Finally found moisture on #1 plug after numerous compression tests, so pulled the head, expecting a blown head gasket.  Nope...the coolant passage over #1 exhaust port had eroded 'till it met the edge of the combustion chamber, giving me inadvertent water injection.  The same ports in two other cylinders were about to do the same thing.  Had our local machine shop weld up the ports, using a head gasket as a template, then surface the head.  Engine now as 226k miles with no further problems of that nature.

 

mike

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+1 TobyB...........Do not let it sit for a long period with coolant in the cylinders,or, certain engine build on the horizon.

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