1990 miata 1.6l blows coolant out the #2 cylinder
Asked by Adam Apr 16, 2022 at 12:35 AM about the 1990 Mazda MX-5 Miata Roadster
Question type: Maintenance & Repair
So my son picked up a 90 miata. This thing is a
project. Blows coolant out of the #2 cylinder an
smokes bad. He wants to replace things piece by
piece instead of just replacing the engine. Is this
cost efective
4 Answers
VRoom12345 answered 2 years ago
Sounds head gasket related, so he will be rebuilding the engine. Rotary engines have their own issues. But yes, it's always more cost effective to install another used engine vs rebuilding due to the labor cost. Since you said it was a project, it sounds like he wants to learn and save some money by doing it himself. But project cars always cost more in the long run as he will be always working on it replacing things to keep it running. Consider it a hobby, as all hobbies cost money.
Head gasket is popped. Not hard to do time engine to number one w front piston at top of cylinder MARK ALL TIMING MARKS W PAINT SO ALL CORESPOND. this is an interference engine. Valve bender. It won't forgive timing errors. This is a super easy head to remove for beginners several peices of cardboard and list where bolts came from poked through will ensure properly placed during reassembly. Repair time 4.5 hrs from disassembly to reassembly once head is back from machine shop.
Get a FACTORY repair manual for proper specs. Remember inch lbs are different from foot lbs. Putting 50ftlbs to a 10mm bolt will result is busted bolts
Cost effective can vary, if the smoke was blue in color then it would be better to go with another engine, or have the stock one rebuilt, however if the smoke was white then it is coolant getting burned and would need the to have the head removed and tested, if it checks good then have it milled flat and install a new headgasket, change the oil and filter. Make sure you use new head bolts.
