Hi all, i’m new to the club and scene after purchasing a 1990 1600.
We had a couple of frosty mornings last week and i had a bit of trouble starting up, (30 seconds or more turning over until success with blue smoke) once up to temperature it runs fine.
I have been advised that it could be the rear temperature sensor but to give the connections a wiggle before replacing.
So I new the cam cover gasket needed replacing so I cleaned the switch connector which had oil inside whilst the cam cover was off.
Also as the cover was off I had a look at the plugs which were black and oily so I had a look inside the pots with a mini endoscope that connects to my phone and the top of the pistons is very sooty but oily wet. After chatting to a couple of friends they have suggested the rings would most likely be the culprit, so I chested the compression which are all 175 apart from number 3 which was 170, ( i didn’t think that was to bad) I also noticed that there looks like oil leaking from the head gasket.
I guess my question is… where to start
It would be handy to know if the cam cover gasket was leaking oil into the plug holes before you took the cover off?
Before doing anything else I would suggest fitting a new cam cover gasket (genuine Mazda) cleaning up everywhere with oil drips/spillage and run it for a while.
It looks like it might have been as there was a little oil on the insulation of 2 of the plugs.
I have replace the cam cover gasket a few days ago and will inspect again this weekend to see if that cured that issue. That shouldn’t have got past the plugs could it?
I had a similar issue when I owned my Mk1. Had oil showing on plug caps, once I’d removed a couple of plugs oil had run down on to the plugs and guessing on to the piston tops. All cleaned up and a new gasket it solved the issue.
You can experience starting issues or rough running if you get oil in the plug wells. Once all the excess oil has burnt off in the cylinders it should be ok.
Not discounting other issues (unknown) but it sounds like cam cover gasket leakage to me. An easy option to replace and see how it goes.
I thought blue smoke indicated worn valve seals, grey-white smoke on cold start potentially rings.
Only fit genuine Mazda cam cover gasket, with the gasket sealant applied in the corners. Tighten as per the tightening sequence to the proper low torque (need a low range quarter inch torque wrench)
Those compression figures don’t look too bad and seem unlikely to cause a starting problem. I agree with saz. Blue smoke, especially on start up, is usually associated with worn valve guides and/or valve stem seals.
JS
