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Mayonnaise

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e21Keith
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Mayonnaise

Post by e21Keith » Wed May 15, 2019 7:41 pm

I have done less than 300 miles since the rebuild and today decided that I would change the antifreeze. There was no sign of oil in the water, other than a very small film which I expected from assembly. I lifted the oil filler cap and it was covered in thick mayonnaise and when I look inside the rocker cover it has mayo in there as well. About 80 miles ago I took the rocker cover off to reset the tappets and it was all clean so this has happened in the last few miles.

I'll start to investigate further tomorrow but I'm going on holiday at the weekend, actually the holiday is now on hold because of an urgent business trip which I can't get out of!

I'll let you know what I find!

On a more positive note I finally fixed the intermittent speedo on my e30 Cabriolet which has been bugging me for the 5 years I've owned the car. After trying everything else I changed the speedo head for a known good one, correcting the mileage to match the old one.



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Jeroen
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Re: Mayonnaise

Post by Jeroen » Wed May 15, 2019 9:53 pm

Some good news, but the mayonnaise doesn't sound promising, especially in these quantities I'm afraid things went wrong indeed. No temperatur problems? Cooling system bled properly? Could have so many causes, warped or cracked head, bad gasket, bad head bolt. Remove the spark plugs first to see if you can find what cylinder is at fault.
Regards/groeten, Jeroen

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e21Keith
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Re: Mayonnaise

Post by e21Keith » Wed May 15, 2019 10:34 pm

Temperature still stable, no outward signs other than mayo.

My suspicion is the head, its a 200 casting and was on the back seat of one of the donor cars. Had it crack tested, pressure tested, looked in all the usual places and it seemed good, but I think the reason it was on the back seat is now clear. The other donor had a cracked 200 head as well.

I have three heads in stock, 200, 731 and 885, I should probably fit the 731 head this time around!

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Jeroen
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Re: Mayonnaise

Post by Jeroen » Wed May 15, 2019 11:02 pm

Grrrr pity all the testing didn't return any failures. Must be the dreaded cam bearing journal.
Regards/groeten, Jeroen

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e21Keith
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Re: Mayonnaise

Post by e21Keith » Thu May 16, 2019 9:54 pm

Checked the 731 head I have today, looks good to me but I'm going to get it all checked out anyway.

Are there any issues, anything I need to know about fitting the 731 head or is it just a direct replacement?

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BertjeConti
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Re: Mayonnaise

Post by BertjeConti » Thu May 16, 2019 10:36 pm

I know, the 200 heads, especialy the early ones are prone for cracking around the 5th cylinder between intake valve and camshaft bearing. Coolant comes through this crack into the engine and mixes with the oil. Not leaking into the combustion chamber(s_.
I've had two in a row, but the third one hold uptil now.
Only difference between 200 and 731 head casting are the intake ports, on the 731 head they are slightly bigger. So it is a direct swap if you use the camshaft which belongs to the engine. Take a note when using another 200 head, ETA engines had the 200 casting head also, but there is a difference in camshaft bearings and corresponding oil gallery, ETA 200 head is a NO GO.
Image Megasquirted '77 E12 520-6

e21Keith
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Re: Mayonnaise

Post by e21Keith » Fri May 17, 2019 7:48 pm

Thank you,

I think I'll go with the 731 head. I'd like to have this all sorted and resolve the running issues by the Silverstone Classic in July which I am attending with my partner. But if I haven't sorted it I'll take the e30 cabriolet.

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