99 s10 extreme 4cyl hesitation
 

Aright guys I know this is t our normal vehicles on this site but I could you a little help brainstorming. I'm buying a 99 s10 extreme 2.2l 5speed with 110,000 miles on it this weekends & it has a rough hesitation in the low rpms (idle- 2500). The guy I'm buying it off of seems pretty down to earth & straight forward so I'm taking his word on the back story. That being that a couple months back he picked up some bad gas at a station somewhere local & it started running rough. He says he dropped the tank & flushed it & replaced the fuel filter about 3 months ago & has been running seafoam with every other fill up. He said he recently did a compression test on all the cylinders & #3 is running 30lbs less then the rest with the rest being at normal psi. It still has a bad hesitation thou when I test drove it last night but can be driven at highway speeds just fine in 4th gear with the rpms around 3000. He has an extra motor he pulled from another 99 s10 that he says has just under 60,000 miles on it. It was pulled for a v8 swap at his shop. Now all that being said I'm gunna pick it up for 2500 with the extra motor & brand new tires on stock extreme rims he was trying to sell anyways. So I'm going to buy the truck couldn't turn it down for a perfect DD. My question to you guys is do you the #3 injector is clogged or could the head gasket be blown? I didn't see any signs of a blown head gasket but it was dark out when I drove it & looked it over.

Based on what you described I wouldn't suspect a blown head gasket. When was the last time he did a tune up? How was he doing the seafoam, threw the gas or intake? If he was treating the gas I wouldn't think it would be a clogged injector.

To the best of my knowledge, in that year the 2.2L was only put in Blazers for the Indonesia market. Unless there is something we don't know about it, I would be very careful on this deal.

Riddle it's an s10 pick up. & I believe he ran the seafoam threw the gas tank. So I'm thinking I'm gunna pull one of the injectors off the extra motor & start with that & if that doesn't cure the problem. Maybe pull the head & check the gasket. If the gaskets good then ill ethier swap the head off the extra motor on it or just put the new motor in it & replace the couch while I'm at it. My fear is the rings are bad but the oil doesn't smell like gas when I pulled the stick. I also forgot that it makes a nice cloud at the tailpipe when it's idling or low rpms. Could tell the color in the street lights thou. It had a funky aroma to it but didn't smell like oil. So I'm puzzled until I pick it up this coming Saturday.

Thanks for clarifying that.

Yep, thanks for the help. So folks thoughts? Injector, head gasket, stuck valve or bad rings?

Just to be safe I would start with the usual suspects, Plugs and wires and the norm that stuff is easier to do that checking heads and doing bigger stuff.

I would pull the dipstick and the oil filler cap and make sure they don't smell like coolant as well.

I know you state he did the compression test, but if you have your own compression test gauge, that should help pinpoint your problem before you start tearing things apart. To paraphrase the instructions on mine:

"a. The needle should travel upscale on each stroke until it reaches it's peak. If it fails to travel upscale on reach stroke, or remains at the same value for several strokes and then starts climbing again before it reaches the cylinder's peak...then you have a sticking valve

b. If the compression is considerably higher than the manufacturers specs, that indicates carbon buildup in the cylinder.

c. If a reading on two adjacent cylinders is 20 lbs (or more) lower than the other cylinders, this indicates a defective head gasket.

d. If the reading on a cylinder is low, pour a teaspoon of 30w oil into the cylinder and then retest the cylinder again. If the readings increase considerably, the fault my be due to to poorly seated or worn piston rings. If the reading remains about the same the valves and/or associated components are likely the cause."

Hope this helps.

Blue that's what I was thinking. KISS Keep it simple stupid! Lol I'm thinking of taking a set of new plugs & wires when I go to get & as soon as I'm outta view of his house swap em out real quick & see if that helps.
50lb I'm planing on looking it over more in the daylight sat. & that & bubbles in the coolant are what I'm gunna be looking for.
Rock I do have a compression tester & ill test it sat after I get home & post the results.