Headgasket replacement cost

[1987 GMC Jimmy]

When you give it throttle, does the noise speed up accordingly?

 

[ajd89]

When you give it throttle, does the noise speed up accordingly?

I would say so hard to hear it with the noise of engine.

Took another video. Ive got some loose rockers but you can hear the noise in question.

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[1987 GMC Jimmy]

Hmm... You know, what about the flexplate and TC bolts? Have you checked those out?

 

[ajd89]

Hmm... You know, what about the flexplate and TC bolts? Have you checked those out?

No I haven't but I can and I will. That was something Craig mentioned too with his truck also. I had thought about it. Dont think its internal? I should be able to see the flywheel bolts to see if they are loose or does this mean pull the trans back?


Bought a 2000 yukon 2 weeks ago had loose torque conveter bolts she made some noise lol. One was finger tight one was out a 1/4 of an inch and the other only had half a bolt left

 

[1987 GMC Jimmy]

I spun a bearing on my Jimmy’s original 350 about four hours after I bought it. I remember it being ridiculously loud and a little higher pitched than that. It doesn’t sound like top end or exhaust noise to me, as every time I’ve had those issues or heard others with them, they’re very ticky. I’m thinking if this is internal, it’ll be in the bottom end, and it might be a good idea to try pulling the plug wires on those other four cylinders to see if you hear a difference. Flexplate bolts do kinda sound like your noise, though, and I know people have mistaken the flexplate bolts being loose for a motor on its death bed when it was perfectly fine.

You can remove the cover and shine a light in that gap to see the flexplate/flywheel bolts. It’s a tight fit but doable. The torque converter bolts are much more visible, but the likelihood is greater for the flexplate bolts to be the culprit. While you’re there, inspect the flexplate for cracks, especially in the center portion, because that can be very bad and also cause noise.

 

[dvdswan]

Have you drained the oil since the knock started? I would cut open the oil filter too. Check for metal shavings in the oil. It's a heavy knock sound which usually is not good. I would take the fan belts off one at a time until they are all off to see if the noise changes. I'm guessing it wont. I hate to guess but it sounds like a main knock, a rod knock would have a double knock each knock. The 1k that would cost to do the heads, you could get bearings, rings, gaskets and possibly engine work done. Rebuilding an engine is not that difficult of a job just time consuming. New engine is around 3.5K, long block.

 

[ajd89]

Have you drained the oil since the knock started? I would cut open the oil filter too. Check for metal shavings in the oil. It's a heavy knock sound which usually is not good. I would take the fan belts off one at a time until they are all off to see if the noise changes. I'm guessing it wont. I hate to guess but it sounds like a main knock, a rod knock would have a double knock each knock. The 1k that would cost to do the heads, you could get bearings, rings, gaskets and possibly engine work done. Rebuilding an engine is not that difficult of a job just time consuming. New engine is around 3.5K, long block.

Its not anything on the front makes it with no belts on it that was the first thing i checked. The oil only has probably 20 mins of run on it I just changed it and the filter. I have a bad feeling its in the bottom too. Its just not the high pitched loud noise the last one I had had which throws me off.

 

[ajd89]

I spun a bearing on my Jimmy’s original 350 about four hours after I bought it. I remember it being ridiculously loud and a little higher pitched than that. It doesn’t sound like top end or exhaust noise to me, as every time I’ve had those issues or heard others with them, they’re very ticky. I’m thinking if this is internal, it’ll be in the bottom end, and it might be a good idea to try pulling the plug wires on those other four cylinders to see if you hear a difference. Flexplate bolts do kinda sound like your noise, though, and I know people have mistaken the flexplate bolts being loose for a motor on its death bed when it was perfectly fine.

You can remove the cover and shine a light in that gap to see the flexplate/flywheel bolts. It’s a tight fit but doable. The torque converter bolts are much more visible, but the likelihood is greater for the flexplate bolts to be the culprit. While you’re there, inspect the flexplate for cracks, especially in the center portion, because that can be very bad and also cause noise.

Pulled the cover didnt see anything loose or cracked but I will look it over better this week when I get time.

 

[1987 GMC Jimmy]

Okay. I’m on the same page as David, I’m afraid, but I think it’s important to exhaust your alternatives before moving to the big enchilada.