I am just wondering why does it matter if the motor is cold or at operating temps when you do a compression check? I checked it when the motor is cold and I am getting weird results.
thanks
Matt

 

i think its because at operating temp. the pistons expand and may give you false readings

 

It should be checked with the motor warmed up if possible.

 

yep, so rings/pistons are expanded to the op. temp.

 

ok I was just wondering. Once I get my car running again I will check the compression when it is warmed up. Thanks
Matt

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by insomniac791 &raquo;</TD></TR><TR><TD CLASS="quote">I am just wondering why does it matter if the motor is cold or at operating temps when you do a compression check?</TD></TR></TABLE>Cold engine cranks at lower rpm with the starter. Warmed-up engine is more consistant, & more representative of compression while running. Oil has been circulating so that's closer to operating conditions too.

It'll work sorta OK on a cold engine (if you can't get it started), but like you say, check it again after you get it running.

 

well when I checked the numbers last night they were
225,180,225,225
today I FINALLY got the car running again and checked them aftedr the car was at operating temps
and it was
225,225,225,225
So I guess all is good thanks
Matt