You can tell compression by the vacuum reading?

[Stkid93]

Is it true you can tell the health of your compression but the vacuum reading? I read that as your compression gets worse your vacuum reading will get closer to 0. So for example, a -10.5 would be a really healthy motor while a -9 means your compresssion isn’t as good (please note the reading must be taken when the car is warm with the air off. ’ot doing this will skew the reading)

While we are on the topic, post your idle vacuum reading from the accessport.

mine is between -10.4-10.6 for the most part.

 

[TyphoonFiST]

Is it true you can tell the health of your compression but the vacuum reading? I read that as your compression gets worse your vacuum reading will get closer to 0. So for example, a -10.5 would be a really healthy motor while a -9 means your compresssion isn’t as good (please note the reading must be taken when the car is warm with the air off. ’ot doing this will skew the reading)

While we are on the topic, post your idle vacuum reading from the accessport.

mine is between -10.4-10.6 for the most part.

Who told you this? The tried and true way to really know is to use a compression gauge and have no more than 10% variation between cylinders.

 

[Stkid93]

i have read this online from multiple sources. I first learned about it when i had my previous car. if you look it up, its all over google.

 

[Dialcaliper]

Poor vacuum can be a secondary symptom, but there are many other more likely causes (like vacuum leaks and emissions components) that it’s hard to say anything about cylinder compression. If you’re suspicious for other reasons, do a compression test

 

[TyphoonFiST]

i have read this online from multiple sources. I first learned about it when i had my previous car. if you look it up, its all over google.

Tell me you're not one those people who think Google is Trustworthy* Trusting google is like going into the back of a van that has Free candy painted on the side.

 

[Stkid93]

well no, thats why im here asking you guys if its true.

 

[D1JL]

Is it true you can tell the health of your compression but the vacuum reading?

Yes, you can tell the HEALTH of your engine using vacuum however, you cannot get true compression.
My question is, why would you want to try, when a good compression gauge set is less than $20.00.

 

[Stkid93]

I don’t want to try nor do I need to. My motor has 12,000 miles on it and is in amazing health. I was just curious if it was true. It seems like an extremely lazy way to test motor health

 

[koozy]

No.