1989 Honda Accord Blue Smoke and CEL

HONDA ACCORD
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COOKIE142
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  • 1 POST
I have an 89 accord, when im driving at a higher speed like on a motorway or freeway after about 3 or 4kms the 'check engine light' comes on and immediately it blows blue smoke for around 30 seconds and then stops but the light stays on, i checked the codes in the ecu and it says Faulty ECU.
Are these two related and does the blue smoke mean i need new stem valve seals or have to replace the ecu or what. its been happening for a while and i have absolutely no idea what it could be... cheers
Oct 9, 2006 at 1:40 AM
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BRUCE HUNT
  • ✓Experienced Mechanic
  • 3,754 POSTS
Blue smoke in any country means the engine is burning oil. This may not be occuring all the time but you need to check these items out. First, does the oil level drop and secondly, I would look at the plugs to see if they show black and oily deposits. Now if the car plugs look gray or brown at the tips that is pretty normal and acceptable. If the car is using oil it would be my guess that valve seals or rings are failing. The CEL, please note that any check engine light that is shown does not necessarily indicate the exact part that is failing or causing the problems. Shorts in wiring, loose connections of wiring etc can trip the CEL and point you IN THE GENERAL direction. Clear the code and see if it returns.
Oct 10, 2006 at 12:14 AM
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Suggested Repair

Blue smoke means the engine is burning oil. Check whether the oil level drops and inspect the spark plugs for black, oily deposits. If the engine is using oil, suspect worn valve seals or piston rings. The check-engine code does not prove the ECU itself is bad; wiring shorts or loose connections can set it. Clear the code and see whether it returns.

Conversation Summary

The owner of a 1989 Honda Accord reports that after a few kilometers at highway speed the check-engine light comes on, the car briefly blows blue smoke, and the light stays on. The stored code indicates a faulty ECU, and the owner asks whether that is related to valve stem seals. The expert explains that blue smoke means oil is being burned and recommends checking oil consumption and plug condition. Oily plugs and oil use point to failing valve seals or rings. The expert also notes that a check-engine code only points in a general direction and can be caused by wiring problems, so the code should be cleared and monitored.

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