Hey guys, maybe y'all can relieve me of a major headache I have right now. I have a 1998 4 door 4x4 Blazer. Recently the truck just took a big ole s*** on me and I need some help figuring out what is wrong with it.

Ok, so the Blazer starts up fine but it constantly misfires. When driving it will stutter and lose power. It also ticks when idling and at very low acceleration. I'm pretty sure this is a valvetrain noise; its like a toc toc toc noise and you can hear directly from the valve cover with a stethoscope. Most recently there has been something spitting out of the exhaust pipe and a little bit of smoke (not a whole lot). I thought it would have a blown head gasket but the antifreeze is topped off where it should be and its not smoking like crazy, nor does it get hot really quickly; it runs at normal operating temp

I may be wrong, but I'm thinking that the misfire is causing unburnt gasoline to spit out the exhaust, but I'm not sure. And a valve is out of adjustment or not getting enough oil. I am not sure and at my wit's end on this!

My truck is super sick and I need help to get her back on the road. Any and all advice is much appreciated!

 

I'm no expert but assuming you are keeping up with all the normal tune up items I would do a compression check or even a leak down test on your cylinders. I would think if you just swab the inside of your tailpipe and smell it you would know right away if it's raw gas or not. As for the smoke out of the exhaust it could be burning oil(compression check).

 

All that and no SES lite or codes? You can have pending codes with no light.

Do a compression test.
Contrary to popular belief not all Head gasket fails are to the coolant system. Also, dont necessarily stop coolant recovery from the overflow bottle. So you need to keep track of the rad being full AND bottle level.

REALLY think you have more than one problem but start by making sure of the mechanicals.

 

Ok. I'll do the compression check. I figured out that it was just condensated water from the cat spitting out the exhaust. I guess I never noticed that before.

The SES light is on, and I've scanned it multiple times and it just reads cylinder 6 misfire. I'm gonna start out on that with new plugs, wires, cap and rotor. Also new air filter: that thing is straight up BLACK

Thank you guys for the advice you gave. It really does help! I'll keep y'all updated.

 

Good news...the blazer is running! Found that the spark plug wire came unplugged and the air intake didn't have a seal on the throttle body. The MAP sensor was also f'ed up, so I had to get a new one of those and an air filter. Now there's no misfire and no sputtering and no smoke! Compression was also good despite the valve tick. Thanks again for all the advice!

 

the pecking in your engine that you are refering to as a valve tick could very well be a hydraulic lifter that is losing it's prime. You could try an oil change and replace one quart of oil with a good quality additive such as Lucas also buy a filter with a built in check valve. I know Wix filters makes these. This could relieve your ticking problem.