1985 V8-S10 Blazer

Update your progress on your various car projects.

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TireSmoker
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Re: 1985 V8-S10 Blazer

Post by TireSmoker »

I took the alternator/water pump belt off before I called for the tow, but no help. I suppose I could get lucky and its a broken fuel pump pushrod, but I've never heard of that happening.

I gotta let it sit for a couple weeks, get the work done on the other stuff, and then come back to this.

Also, I insured the truck with Hagerty this year (along with the Chevelle). They covered the first 150 miles of my tow. For a 168 mile tow home, I was only out of pocket $108 and another $20 for his return tolls. I was pretty happy about that.

-Dave
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Re: 1985 V8-S10 Blazer

Post by MostMint »

When you get back to it here are some things to look at:

fuel pump itself
timing chain gear bolts
maybe a rocker stud is coming up

Since the oil pressure is fine I'm having a hard time believing its lower end, but I suppose an oil filter autopsy would answer that real fast.
[quote="Basement Paul"]Is that a mint rocketship on the hood?? :shock:
-BP[/quote]
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Re: 1985 V8-S10 Blazer

Post by TireSmoker »

I dont think it's a rocker stud -- they're screw-in studs. Timing chain bolts sound plausible. I could get lucky, labor wise, since the engine sits high enough in the chassis, I may be able to pull off the oil pan (so to pull timing cover) in the vehicle. Fuel pump and/or pushrod -- I couldn't get that lucky, unless I let it sit 6 months before looking at it -- "oh, that's all it was?!?"

On a related note, I bought a set of wheel dollies at Harbor Freight and the truck is surprisingly difficult to move around on them. Disappointed in that purchase.

-Dave
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Re: 1985 V8-S10 Blazer

Post by TireSmoker »

So I finally mustered up a little motivation to start checking this thing out. Here's the noise that ended my Carlisle Adventure..

-Dave

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Re: 1985 V8-S10 Blazer

Post by MostMint »

look under the valve covers then check the oil filter. hard to tell from video how deep inside the engine the sound originates
[quote="Basement Paul"]Is that a mint rocketship on the hood?? :shock:
-BP[/quote]
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Re: 1985 V8-S10 Blazer

Post by TireSmoker »

I checked under the valve covers before the tow truck arrived. Looked good to me. I cut the oil filter open tonight, but I'm not seeing any real obvious garbage. I did glue a couple magnets to my drain plug, but havent drained the oil yet.
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Re: 1985 V8-S10 Blazer

Post by wxo »

I suggest using the old trick of putting your ear to a screwdriver or broom handle and listening all around the engine to locate the source of the noise.
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Re: 1985 V8-S10 Blazer

Post by GMJohnny »

It knocks heavily when at idle, then goes away a bit when throttle is brought up, then becomes
more pronounced again when revved higher. I'd look for the harmonic balancer or the
timing gear assembly being loose. ( I think you've already loosened all of the belts to eliminate
the water pump, power steering and alternator. ) Do you always get valve train clicking? Seems
there's a bit of that in there too, but that might just be the motor.

GM
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Re: 1985 V8-S10 Blazer

Post by TireSmoker »

After a suggestion to actually pull the pleating apart on the cut-open oil filter, I'm seeing plenty of metal fragments, confirmed by running a magnet and picking up pieces. The engine will be coming out. It's just a question of how much collateral damage there is.

-Dave
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Re: 1985 V8-S10 Blazer

Post by TireSmoker »

Got the engine out last night. Paul came over in the evening and we had it out in probably 10 minutes since I already had everything disconnected.

After some disassembly and inspection, it appears that the timing chain was making contact with the cover. Luckily, the cam and lifters all look fine. We didn't pull off any rod or main bearing caps, since it still had oil pressure.

The plan right now is to replace the timing chain, timing cover, oil pan.

-Dave
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Re: 1985 V8-S10 Blazer

Post by GMJohnny »

Any guess as to WHY the timing chain was rubbing the case?

GM
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Re: 1985 V8-S10 Blazer

Post by TireSmoker »

Because it's junk I bought off ebay?? Not sure other than that. We measured depth of the cover from the mounting flange, and the old stock-like steel one that was removed was 0.1" deeper, which certainly seemed like enough extra clearance. I checked a couple ebay listings of a similar looking part to see if there was any mention about only using a single-row timing chain, but nothing found.

-Dave
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Re: 1985 V8-S10 Blazer

Post by TireSmoker »

Further inspection has revealed that the #1 rod bearing is indeed bad. No doubt about it. I can jiggle it on the journal with my fingers.

-Dave
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Re: 1985 V8-S10 Blazer

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Re: 1985 V8-S10 Blazer

Post by Maverick »

How is the cam end play?

Sorry to see you report a rod bearing issue. I know how it feels to spend a bunch of money and have an unsatisfactory result. Hope the crank isn't damaged.
Maverick
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