compression test result help

[TBCobra]

So I'm looking at purchasing an '04 cobra and had the dealer do a compression test.

I don't remember the exact numbers but all were between 155-170 except cylinder #4 which had 130 I believe. Is this something to be concerned about?

Car has 25k miles. Not sure if they did it when the motor was warm/cold/hot or what. I would assume cold or just barley warm.

 

[bigmoose]

I would assume the dealer did it right regardless. With one that low I'd pass and tell them why.

 

[TBCobra]

I would assume the dealer did it right regardless. With one that low I'd pass and tell them why.

That's what I'm thinking. They actually paid and had a guy come in and test them. The tech was telling me how Ford says if the lowest is within 75% of the highest reading it's okay. I thought it was more like 10-15%. Yeah I'm gonna pass, really glad I had them do this.

 

[Mojo88]

Smart move to get compression test. Not many folks do that..... but they SHOULD!

 

[01yellercobra]

That's what I'm thinking. They actually paid and had a guy come in and test them. The tech was telling me how Ford says if the lowest is within 75% of the highest reading it's okay. I thought it was more like 10-15%. Yeah I'm gonna pass, really glad I had them do this.

I'm pretty sure it's 25%. At least that's what I usually aim for. Whether or not I'm right is another story.

 

[Zemedici]

No usually 10-15% of each other, and all want to be around 165-180.

Could have done it incorrectly, however. Any check engine lights? Misfire?

 

[TBCobra]

I passed on it already. The big problem was it's far away from me so I was basically going to buy it sight unseen. It's a low mile ow with the dark insert seats and pretty close to stock. Has the pulley cover and everything but that one cylinder being lower than the others was concerning enough. Plus the price wasn't great.

I can't take the chance of it having any issues.

 

[Mojo88]

I passed on it already. The big problem was it's far away from me so I was basically going to buy it sight unseen. It's a low mile ow with the dark insert seats and pretty close to stock. Has the pulley cover and everything but that one cylinder being lower than the others was concerning enough. Plus the price wasn't great.

I can't take the chance of it having any issues.

You, sir, are a wise car shopper. There are PLENTY of vehicles out there. For me, I actually enjoy the searching and buying process. But the key is to keep looking until something special appears on the radar screen. Even still, there's always a risk, but the key is to minimize that risk, as you are doing. Well done!

 

[TBCobra]

You, sir, are a wise car shopper. There are PLENTY of vehicles out there. For me, I actually enjoy the searching and buying process. But the key is to keep looking until something special appears on the radar screen. Even still, there's always a risk, but the key is to minimize that risk, as you are doing. Well done!

Wish I could say that about all of my vehicle purchases. lol. Rewind a couple years ago where I got screwed by a member on here with an '03 cobra. Sold it a month after I bought it for a huge loss dude to a engine issues. Maybe I've learned my lesson. ha.

Regardless, thanks!