m42 overheated

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Avtovaz

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m42 overheated
« on: November 28, 2011, 03:08:37 PM »
my m42 motor overheated on t eh weekend, not exactly sure how, but it had a hard run, then stopped, and driven slowly for 2-3 km. when i stopped i heard water and steem comming from the bonnet area but as i had not long been threw water, i thought it was just water exapotrating off the rad etc.

I was checking the temop guage, and it was fine. I noticed the car went onto 3 cylinder, and it was then i stopped , the car cut out. I tried to start it again and the starter a 325i one would not turn the motor very fast at all.

When it cooled the motor turns liek it has no compression.


I think when i went threw the water a stick has wedged teh viscus fan, and whe i stopped the motor got hot quite quickly. Then driving off its started to cool down and then the damage has happened.


some questions

at no point did the temp guage go up, it was always on normal, but it had no water in it, why was that?

what is likely to be salvagable from this motor? I mean, i just rebuilt it and i dont want to throw it away but having said that, there is a 200k m42 on ebay cheep, and also there is a m44 for £300

what should i do?

thanks!

DesktopDave

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m42 overheated
« Reply #1 on: November 28, 2011, 06:37:44 PM »
The temp gauge is heavily buffered.  It'll be in the middle unless the engine is really cold or overheating enough to blow a gasket.  I'd figure it would have done something too, but it's so inaccurate.  More like a warning light than a real gauge.

I guess you can't test the fan, I'd do a quick compression or leakdown test to see what's going on.

Hopefully that water wasn't too high.  I'd worry that some water got sucked into the intake...if so you might have hydraulically locked the engine...that's bad.
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cncmastr

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m42 overheated
« Reply #2 on: November 29, 2011, 04:42:00 PM »
Did the needle feed all the way to the right, in the red?