Hi all!
Wanted to post a few pictures up here in hope that someone can help with some advice. I have had an engine rebuilt (998cc +20 overbore with pistons, rings etc. to match) and have just finished the first part of running it in (500 miles) and changed the oil. Very sweet running engine and really pulls nicely from the careful driving it has had until now.
I noticed however that after torquing the head down to Haynes Manual spec of 68Nm/50 lb.ft and setting the tappets (at the same time as changing the oil at 500 miles), there appears to be a very small seep/weep of coolant coming out from the head/block joint at the head gasket and running down the block in 2-3 places between the head and block, nothing when the engine is warm or bone cold, but seems to be when parked up after a run and when everything is cooling down (I assume as the head and block contract and there's less sealing pressure on the gasket).
When I noticed the leak from a couple of spots I checked the head torque again the next day to be safe (completely cold, spiral pattern), and was surprised to find the middle nut of the ones outside the rocker cover and one of the ones next to it (can't remember if it was left or right) was slightly off torque whereas the rest were fine, maybe 1/8th turn of the nut to get it back to torque. Studs are "Y" marked. Took it for a drive this evening, a very minute trickle has come out and have now parked the car to cool completely and see what happens later as it cools.
I can see it has a copper gasket fitted and have read here they can be hit and miss unless the block and face are 100% clean. Everything was freshly machined before assembly, and from the quality of the rest of the build I assume it was nice and clean, but you never know if there's something stopping it laying absolutely flat, a burr or a tiny piece of grit... Not sure how big a speck of dust needs to be before the copper gasket has issues
There are no symptoms of any overheating, even in traffic with an electric fan to help the mechanical one when stationary, it has never overheated, there's no white smoke from the exhaust, no rough running (it has a fast road cam but it's not any lumpier now than it has been), nothing in the oil to say coolant is getting in there (mayonnaise), and no drop in coolant level, in fact everything else sounds, looks and feels 100%.
I have attached images, hopefully someone has a few suggestions. Either the leak stops by itself (I never rely on this ) or I'll fit a new gasket to fix it and be safe (I have heard composite is the way to go, suggestions please for the best ones for a 998). However even if weeping is not going to cause issues, I can't have it leaking a few drops all the time as it looks ugly on the freshly painted engine
Does anyone have experience with this type of leak? I have seen pictures of other minis with the same leak patterns down the block, but would prefer to be leak-free for peace of mind! If anyone needs more info I'll answer as best I can
- John
Attached Files
Edited by mini_pooper, 16 April 2018 - 06:20 PM.