Question : Slightly over heated lost block heater

[bob442]

So I was leaving work and I had no heat, then the engine compartment started smoking, shut her down, the heat got on the gauge got about half way, found out my bolt in style frost plug to replace the block heater shot out, I got it back to work by towing it, got a block heater today, ran it up, and at first it was all good for about 15 minutes idling then I started getting a high idle to about 1900rpm, and after a minute it would go down to normal. So I took it for a spin, it sounds like its running really smooth, she runs cool, but now I have no power and it's shifting at 4500 rpm at wot instead of 6900-7200, and I'm way down on power, she will rev up to 7500 in neutral, and it kinda has power for a second when you hit it but then it kinda falls flat on its face.
I noticed a very small vaccum leak from a ss line to my oil catch can but playing around with it while it's acting up with the idle high or not makes no difference. Any ideas? I'm thinking I cracked something in the top end, or a head gasket is giving me false reading due to a coolant being burnt, I have white smoke out the tail pipe, but I have to cat right now, it's cold outside, and I smell nothing but normal exhaust out the tail pipe.

[bob442]

well, limped it home, after driving it, i noticed if i manually put it in first all my power was back, so it lead me to believe my mass air was getting screwy readings, sure enough, my oil catch can had 1/4 cup of straight water in it, and some oil, and that had gotten into the throttle body and down to the mass air flow sensor. i just brake cleaned it all and seems to be all back to normal (fingers crossed)

[pocket-rocket]

I wouldn't use brake clean on a MAF. I've read that isn't good for them. They make stuff to clean them. Expensive stuff, but you don't hose a MAF down like you do brakes.

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[bob442]

It's all I had on hand, non the less the issue hasn't gone away, it will start up cold reving as high as 3000rpm, will stay there for 10-15 minutes, seems now once I've driven down the highway for a bit, and come to a stop the idle all of a sudden drops down to normal and my shifting it's somewhat normal, my mass air readings are down 20-30 m/s on WOT when the car is idling high, o2 is 14.7 cruise and 12.7 WOT regardless of the issue, maybe I'll get some sensor cleaner and spray out the MAP, but it seemed to be reading the same when it was acting up, 8 psi cruise issue or not and 15 WOT

[bob442]

Ended up being the tps, it was hard to catch messing up on the scanner, but eventually I saw 4% open at idle, and wouldn't go past 79% at wot. Then the water pump took a shit. So I put in a new one with the steel prop. Instead of the reman aluminum prop, driving temps down considerably

[unchained01]

glad you found it !!!

[TGP37]

So I put in a new one with the steel prop. Instead of the reman aluminum prop, driving temps down considerably

Also providing better in block pressure which drives the boiling point higher. Even though the system is closed and bleed at 15 psi from the rad cap, the TStat is enough a flow restriction where the water pump can provide good pressure. Holding off flash boiling at the cylinder walls, which can create a steam jacket preventing good thermal conductivity.

Though I don't know what temps are around the cylinder jacket but I imagine they reach boiling point easily at times. I've heard of steam pockets in the top of heads.

[bob442]

I can happily say my mystery small coolant leak I gone, it was so little that I would never see a drop, and never be able to pressurize the system enough to see it leak either. So the leak had to be at that block heater plug.

Now my lifters are getting noisy again, gonna order some stock new Gm ones. And maybe do a 3500 top swap next summer, I wanna push for over 300hp. Maybe a bigger cam if my timing chain didn't stretch again.

[3400-95-Modified]

I can happily say my mystery small coolant leak I gone, it was so little that I would never see a drop, and never be able to pressurize the system enough to see it leak either. So the leak had to be at that block heater plug.

Now my lifters are getting noisy again, gonna order some stock new Gm ones. And maybe do a 3500 top swap next summer, I wanna push for over 300hp. Maybe a bigger cam if my timing chain didn't stretch again.

How are your "lifters getting noisy again"? Are you sure its the lifters? I have the LS6 internals and haven't really had any issues that I can say are noises directly related to the lifters themselves. Granted my top end isn't silent but what do you expect with 516/568 lift and 216/240 duration... I had a very noisy setup which I then swapped to LS6 internals and the noise still persisted... it was only after changing my timing chain did it go away. Honestly I wish the HY-VO chains were just a touch tighter because I think most of the noise we hear is the chain slapping the center dampener.

[bob442]

It could be the chain, very well could be, the motor once was quiet for about 3000km after i replaced the timing (drtc) my first one was stretched considerably, but I did a lot of things when I had the motor out, a new set of tce lifter spring, chain dampener, and 10mm rockers. I did for sure have a lifter issue before, now, my noise is like, well, like a small tow type chain getting rotated. It gets loud sometimes. Other times I almost don't hear it at

[3400-95-Modified]

I didn't know you had a DRTC, I was referring to a stock style 96 3100 chain that I had go bad on me and after replacing that the majority of my noise was gone. I wouldn't think the DRTC would hit that much, IIRC when I did Roberts, it was a pretty tight chain.

[bob442]

Yeah so was mine, I've clearanced the timing cover 3 times in total, once before I assemballed the motor completely, once with out the gasket an the motor assemballed (cleared) and then again a few months ago, some how the chain was still slightly hitting on the bottom, all the chain slack lead me to believe something wasnt aligned properly but a straight edge, everything was good. Then I checked end play and still everything was good, so I ordered a chain and put a new one in about 5000km after I rebuilt the motor.