Toyota T100 Compression Test: how low is too low?

[iski123]

I'm looking to buy a 97 with the 3.4L 5VZ-FE. It's got higher kms' (316k) but has been meticulously maintained (with great records) I had a compression test done and the result was 150 in all cylinders. Now the recommended range for the engine is 145 to 175 (or 170 can't remember) and I am a little concerned that 150 is getting down pretty low. The mechanic who did the test said he thought it was a good result considering the mileage and noting that the uniformity across cylinders was a good indicator that it had been regularly and well maintained. I don't really know the mechanic and was just hoping to get a second opinion on the matter... so what do you think? is it acceptable for the pressure to be low and consistent or should I steer clear of this one?

[1000-oaks]

I wouldn't rule it out at an even 150, if it's nice otherwise. If it had some at 125 I'd walk.

[iski123]

cool... actually just called the local dealership and they said it's decent considering the mileage, I think I'll go ahead and get it.

[tripice351]

150 is definitely acceptable, and uniformity is also a very good thing. To really put your mind at ease, test drive it when it is stone cold - a rough idle or misfiring would be a bad sign. Worn rings or valves will often seal up after the engine gets a little bit of warmth in it (often within 1 minute of running).

[spencea]

Since you got the same on all cylinders i wouldn't worry about it. just because the range goes up to 170ish doesn't mean they rolled off the factory floor like that it lost 20psi in 13 years. The factory spec is that broad because compression tests are are not very accurate. You could test it again the same day and get different values, as long as you fall in the range your good.

Like the mecahnic told you you want to look for uniformity, not how big the number is. Yes a race built engine you would pay a bit more attention to the psi so you can tune everything to run at a higher peak, but for you purpose uniformity is the key.

[axebiker]

Wow...that's a ton of miles. Lots of considerations beyond engine compression. 14 years old... I know it's a Toy, but wow.

[Mannix]

To add to it, altitude affects compression readings. IE, 150psi at 4000' might be 160psi at sea level. Sounds good to me.



Iain

[Chugachjed]

Wow...that's a ton of miles. Lots of considerations beyond engine compression. 14 years old... I know it's a Toy, but wow.

Thats less than 200K miles. Canuks use kilos.

[axebiker]

Ah...not quite as "WHY???" now...

Thx. Carry on.

[1000-oaks]

Wow...that's a ton of miles. Lots of considerations beyond engine compression. 14 years old... I know it's a Toy, but wow.

That's nothing for an 80s or 90s Toyota if made in Japan, that's about the age I look for when shopping for a "new" one. Can easily get another 100k out of it without fixing anything serious.

The last 10 years of Toyota if made in the US...about the same as a Ford, which is at the top of the heap of "domestic" vehicles.