ok I had my mechanic do a compression test yesterday and we got a churping noise in cylinders 1 and 3 and he had never heard this noise before!!! the compression measured 180 on all cylinders which he told me was normal for 9.5:1 pistons. I have a built LsVtec motor with cp pistons 9.5:1 81.5mm bore and eagle rods. so has anyone heard this noise before on a compression test??

thanks

-dan

 

any ideas???

 

only thing i can think of is piston slap. you have more clearance at the top of the piston than at the bottom of the skirt. until the face of the piston heats up and expands it will "slap" the cyl walls. i could be wrong but thats my guess

 

well we made sure the car was warmed up before we did the test but maybe could be that????

 

it happens all the time. how many compression tests has your mechanic done? its perfectly normal.

 

well he is well know to be one of the best mechanics here in town but that was the first time he heard that noise