OK so a guy from work picked up a 4/98 e36 sedan for about a grand knowing it had headgasket/head problems. 215k, black/black, AT, pretty good condition for age, a little surface rust but overall good. He would like to just use it for a daily driver. Engine ran good before teardown, just intermittent temp spikes from the leakage. It had been worked on by a mechanic that doesn't know BMW's, replaced a couple hoses, new water pump, thermo, and fan clutch and thought that would fix it. I told him I would work on it for him, started tearing it down, head has 2 cracks, cyls 2 and 3 from exhaust valve seat to coolant passage. Cylinder bores look good, no step at the top, no scratches, haven't measured the bore yet bot honing marks are still there. Problem is that there is a ton of nast in the coolant passages of the block. Looks like aluminum corrosion that migrated from the head. My question for you guys is do I just flush out he water jacket on the block as best I can and drop a good head on. Or find a used running engine and swap in. I don't think its worth tearing down the bottom end for a full rebuild as the money really starts flowing then. I don't have a problem with doing the work as I have done a full rebuild on an m50 and m20. I will get a few pics up so you can see what it looks like tomorrow. And let this be a warning to everyone, maintain your cooling system!!! Cracked heads around the exhaust valves are from hotspots due to corrosion buildup in the coolant passages. Change your coolant to keep its corrosion inhibiting properties good.
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jc43089
OK so a guy from work picked up a 4/98 e36 sedan for about a grand knowing it had headgasket/head problems. 215k, black/black, AT, pretty good condition for age, a little surface rust but overall good. He would like to just use it for a daily driver. Engine ran good before teardown, just intermittent temp spikes from the leakage. It had been worked on by a mechanic that doesn't know BMW's, replaced a couple hoses, new water pump, thermo, and fan clutch and thought that would fix it. I told him I would work on it for him, started tearing it down, head has 2 cracks, cyls 2 and 3 from exhaust valve seat to coolant passage. Cylinder bores look good, no step at the top, no scratches, haven't measured the bore yet bot honing marks are still there. Problem is that there is a ton of nast in the coolant passages of the block. Looks like aluminum corrosion that migrated from the head. My question for you guys is do I just flush out he water jacket on the block as best I can and drop a good head on. Or find a used running engine and swap in. I don't think its worth tearing down the bottom end for a full rebuild as the money really starts flowing then. I don't have a problem with doing the work as I have done a full rebuild on an m50 and m20. I will get a few pics up so you can see what it looks like tomorrow. And let this be a warning to everyone, maintain your cooling system!!! Cracked heads around the exhaust valves are from hotspots due to corrosion buildup in the coolant passages. Change your coolant to keep its corrosion inhibiting properties good.
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