[lemansbluen54]

Hi all, recently I had a motor start smoking like crazy at around 188k miles, turns out it had low compression numbers. I purchased a used motor with around 90k miles and 160-165 compression in all 6, I did verify this after the motor was put into my car. after around 2 months and roughly 2000 miles, it started smoking yet again. compression showed that cylinders 2 and 3 took a dive and the rest were still as they should be. Given that I purchased a used motor, I understand that nothing is guaranteed, but 2000 miles seems a little too soon to encounter this again. If anyone has an idea to any factors that may cause this please feel free to share!

[Mustafa.e92]

Did you reuse the injectors from the old motor? If you put the injectors in the same cylinders on the new motor is their any correlation between the ones that lost comp? could have an injector that shat itself and is fuel washing the cylinder. Could also be a tune issue

[lemansbluen54]

Originally Posted by Mustafa.e92

Did you reuse the injectors from the old motor? If you put the injectors in the same cylinders on the new motor is their any correlation between the ones that lost comp? could have an injector that shat itself and is fuel washing the cylinder. Could also be a tune issue

I did reuse them but didn’t place them in any specific order, will send them for testing. As far as the tune I’ve been on the same map for over a year and a half, doubting that it’s tune related given that all this started occurring over the past few months. I’ll post the compression numbers from both motors shortly.

[lemansbluen54]

Motor 1:
85
150
115
120
165
140

Motor 2:
165
90
75
165
165
165

Important thing to note here is that the car was involved in a fire on the valve cover, local fire department and insurance determined it to be the injector harness that caused it. The injectors on the first motor were swapped for a low mileage set of index 12s after. Running them on this motor as well but I don’t believe that they were put into the same spots.