Thanks Wes! I don't think your phone misrepresented anything, it sounds really bad right now.
CK5
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1989 K5 - Gradual Learning
- Thread starter shima
- Start date
First 4x4 - learning basic maintenance / upkeep and maybe some small mods.
Thanks Wes! I don't think your phone misrepresented anything, it sounds really bad right now.
Mine started in 34* weather after sitting for two weeks and didn’t sound anywhere near like that with 10-30 oil in it.
It sounds like you have an exhaust leak to me, it's rhythmic so I doubt it's mechanical, it's explosions.
I could be wrong but if it was metal on metal it would be more even rythm, this sounds like the rythm changes with misfires
Sounds like a massive exhaust leak to me too. Either the donut at the manifold on one or both sides is blown out or it's a big crack in a manifold. Could be a loose/broken bolt or two, but it's a big leak.
I'd look under it for an exhaust leak. You'll usually see a sooty black trail coming off of the leak.
I'm wondering if your ECM is giving you fits.
Thanks for the support guys, as always!
Man, I am pretty sure that @Justin V said I had an exhaust leak years ago when he came out to take a look at my Blazer. That was when I first bought the thing. I bet it just got worse and worse over time. I'm dumb to have forgotten about that. Perhaps now is the chance for me to ditch the factory Y-pipe and go toward true dual exhaust. Hopefully once the exhaust leak is fixed it won't be vibrating so much. From there I just need to diagnose the low power.
Man, I am pretty sure that @Justin V said I had an exhaust leak years ago when he came out to take a look at my Blazer. That was when I first bought the thing. I bet it just got worse and worse over time. I'm dumb to have forgotten about that. Perhaps now is the chance for me to ditch the factory Y-pipe and go toward true dual exhaust. Hopefully once the exhaust leak is fixed it won't be vibrating so much. From there I just need to diagnose the low power.
I hope not brother! It does sorta feel like the truck is in "limp mode".
I had similar issues that you're having with an S-10 Blazer I used to have. It took a couple of months to track it down due to it running great for periods of time making me think I had it fixed. I finally got some help from a GM tech buddy of mine to finally pinpoint it. From what I recall the reman ECM cost me under $100.
You'll have to check out dual exhaust works with emissions. I think you can do it with a cat in each pipe, but I don't know for sure.
If you have an exhaust leak before or immediately after the O2 sensor, that will have a big effect on what it's reading and how well the truck runs.
If you have an exhaust leak before or immediately after the O2 sensor, that will have a big effect on what it's reading and how well the truck runs.
Yeah, I am pretty sure I would pass fine so long as each pipe has a cat. The thing is that I can't find a true-dual "manifold back" system that has cats on each pipe. I contacted Summit a while ago and asked whether they sold anything like that for the 350 and they said they don't. Couldn't find anything online either - all I came across was headers without cats in them. I'd like to keep my stock exhaust manifolds cause I figure it would be cheaper to do it that way, but I might be wrong. Still a lot to learn in the exhaust space.
Yeah, I don't think anyone sells a kit. About the only option is one of the universal builder kits or piece it together yourself. I've been doing the latter using mandrel bends and straight pipe. I call it Frankenstein exhaust.
I think because your truck came with single exhaust and a cat by EPA laws that's all you're allowed to replace it with which is why you're not finding dual kits with cats.
That would be a Federal law too, so whatever CO says wouldn't matter.
I am starting to get back into the garage a little bit. My back is starting to feel better. I start to feel pain after a little while but I can manage some garage sessions so long as I try and keep decent posture. Difficult to do when you're sitting inside an engine bay or laying under the truck, but I can last about an hour or two before I need to stop.
Anyhow I went out yesterday and looked for exhaust leaks. I found a minimum of SIX!
After finding the leaks I went to AutoZone and bought the product from the YouTube video. $12 per, not awful I guess. I bought two of them.
https://www.autozone.com/sealants-g...d-extremeheat-organic-repair-paste/435518_0_0
I was talking with my buddy last night while we were hanging in the garage. The Blazer has been down since late September... over 3 months now. A lot of that is due to my injury, but it is still disappointing. I gotta get out there as often as I can now that my back is starting to heal up.
So anyhow, my next steps for the exhaust leaks:
Anyhow I went out yesterday and looked for exhaust leaks. I found a minimum of SIX!
- Driver side exhaust manifold - where the manifold meets the head - port closest to firewall.
- Driver side exhaust manifold - where the manifold meets the head - port closest to bumper.
- Passenger side exhaust manifold - where the manifold meets the head - port in the middle.
- Passenger side exhaust manifold - where the manifold meets the head - port closest to bumper.
- Passenger side exhaust manifold - "body" - giant freakin' crack and small hole between the port closest to firewall and port in the middle.
- Driver side exhaust manifold - "flange" or "clamp" where the manifold meets the exhaust pipe.
After finding the leaks I went to AutoZone and bought the product from the YouTube video. $12 per, not awful I guess. I bought two of them.
https://www.autozone.com/sealants-g...d-extremeheat-organic-repair-paste/435518_0_0
I was talking with my buddy last night while we were hanging in the garage. The Blazer has been down since late September... over 3 months now. A lot of that is due to my injury, but it is still disappointing. I gotta get out there as often as I can now that my back is starting to heal up.
So anyhow, my next steps for the exhaust leaks:
- Tighten the bolts that attach exhaust manifolds to cylinder heads? Not really looking to remove the exhaust manifolds unless I have to. Could always fix the other two major leaks and see how it sounds / runs.
- Remove the heat shield from the passenger side exhaust manifold so that I can get at the full crack / hole with the putty.
- Apply some putty to the leak at the manifold/pipe mating area.
- Set timing back to 0. It's still advanced from the last time I was messing with it.
- Use q-tips to clean up the insides of the wires, use rags to clean up the spark plug ends and the distributor cap ends.
- Redo the test where you put the test light in-between the spark plug and the spark plug wire. Take good video while doing it.
- Post up in The Garage with the videos and an explanation of what I did and what I've checked thus far.
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Am glad you are on the mend, back issues suck.
I forget if k5 or k30. Small block chevy if there are gaskets between head and exhaust manifold take them out and through them away. Go metal to metal. You'll want to replace the cracked manifold.
Maybe a new head pipe doughnut will fix the last one.
Soak the studs and nuts in penetrating oil. Not wd-40.
What color are your exhaust manifolds. Post up a picture.
I am wondering if your cat might be plugging up, could explain your drivability, the cracked manifold and leaks.
I forget if k5 or k30. Small block chevy if there are gaskets between head and exhaust manifold take them out and through them away. Go metal to metal. You'll want to replace the cracked manifold.
Maybe a new head pipe doughnut will fix the last one.
Soak the studs and nuts in penetrating oil. Not wd-40.
What color are your exhaust manifolds. Post up a picture.
I am wondering if your cat might be plugging up, could explain your drivability, the cracked manifold and leaks.
@Wes Harden this build thread is for my K5. I will go out and soak the bolts in penetrating fluid. I got a bunch of PB Blaster in the garage. I'll snap a photo of the manifolds but you can see them in this short video I shot yesterday.
You run no exhaust manifold gasket?
Yeah I bet the doughnut in there is destroyed, and yeah I have been told numerous times to replace my cat. I don't know how to weld so I've always been dragging my feet. I should just commit to getting rid of that thing.
You run no exhaust manifold gasket?
Yeah I bet the doughnut in there is destroyed, and yeah I have been told numerous times to replace my cat. I don't know how to weld so I've always been dragging my feet. I should just commit to getting rid of that thing.
yes I never run exhaust gaskets with stock manifolds. the color looks ok in video. I was looking to see blackish blue, if you see that color manifolds have been very hot.
When you do the exhaust manifolds, they sometime will shrink in on the ends. Enough so that the bolts will be a pain in the ass to get back in. It looked like there are gaskets loosen all the bolts with out removing, the gaskets are cut out on the bolt hole bottom side. Check for gasket sticking to parts and remove. When you re-tighten start in the middle then alternate out to the ends. warm up exhaust and re-tighten again, warm. there may still small leaks these should stop with a little use.
Have a muffler shop do your cat, if you need to get it replaced.
When you do the exhaust manifolds, they sometime will shrink in on the ends. Enough so that the bolts will be a pain in the ass to get back in. It looked like there are gaskets loosen all the bolts with out removing, the gaskets are cut out on the bolt hole bottom side. Check for gasket sticking to parts and remove. When you re-tighten start in the middle then alternate out to the ends. warm up exhaust and re-tighten again, warm. there may still small leaks these should stop with a little use.
Have a muffler shop do your cat, if you need to get it replaced.
Thanks for the tip @Wes Harden. I pulled this out of the area where the manifold meets the exhaust pipe. Is this what they call a donut? Can't really tell if this one is bad, but it looks like they're cheap to replace. Has a bunch of cracks in it but I don't know if that would cause the exhaust leak that was happening in that spot.
nothing I can point to and say thats it. Any dark black streaks on doughnut? how tight was the flange ? All the nuts equally tight ? when you install the new one tighten the 3 nuts a little at a time evenly.
Yeah I'm wondering if my flange was just loose. Going to take a look at the passenger side and compare.
Earlier you gave me a tip about removing the exhaust manifold gaskets... I am guessing that I should hit those with PB Blaster the night before I try and loosen em.
Earlier you gave me a tip about removing the exhaust manifold gaskets... I am guessing that I should hit those with PB Blaster the night before I try and loosen em.
