3400 Misfire and temp increase - HG?

[Azrael]

It wouldn't hurt to try a coolant flush. Check and see if the radiator is hot from top to bottom. Clogged passages would obviously be cooler.

I just replaced my headgaskets. While there was no sludge in the overflow tank there was some buildup on the coolant passages on the old headgaskets.

[bszopi]

Even though I really don't want to deal with it right now, due to a bunch of other crap going on, I may just say fuck it and replace the head gaskets anyway. I'm almost tempted to bring it in, as I just don't have the time to mess with it right now, but I just hate being raped by a mechanic, especially on something like this...

[Tbay99Venture]

Well if you aren't losing water, and you've been seeing the temp problems get worse but still don't lose water then it's hard to make a case to do all the extra work.

Our vehicle had around 160,000 miles or so in 10 years and has always run Death-cool or the Prestone equivilant. There was crud behind the head gasket holes but the holes themselves weren't obstructed. However, we had replaced the radiator anyhow since the plastic near the return hose fitting was split. (The epoxy you can buy made a good temporary fix so we could go camping that weekend.) I got the radiator in place and then the lame J-shaped hose to the rear heater started leaking. Fix that and the craptacular plastic Tee snapped a week later. I thought I inspected the plastic pretty well so my new rule is don't trust the plastic. Sorry, way off topic. Just trying to give you a baseline that the cooling system clogs might not be the issue. We get hot weather here well through September but the old radiator never had problems keeping the temp needle in the bottom range even in city traffic with the A/C on.

You can certainly take the hoses off and see that it flows out as fast as the garden hose can supply it. Then you could also check via the pump inlet & see whether the pump impleller has broken free.

[bszopi]

Well, this might explain some of the issues, including the toy train sound I was hearing...



Head doesn't look too bad... :crosses fingers:

[bszopi]

Anyone ever helicoiled a spark plug hole at home? I'm contemplating it, as the new spark plug appeared to be leaking as well. So I tore it all down. I've got the front head off, still need to take the plugs out to look at the hole better. Just trying to decide if I want to try to do it myself, then put it all back together tomorrow, or take the head to a machine shop to have them fix the hole, then reassemble Mon, and possibly Tues evenings.

I may need to source a new crank sensor wire as well, as the current one got in contact with the exhaust manifold. It doesn't look like it melted down to the wires, but the 2 insulations are definitely melted together. And of course, I broke all 3 crossover studs, so I need to get some of those as well.

[BLADE]

I had a helicoil in a truck and the spark plug stuck in it and broke the plug off in the head donot recomend a helicoil or definitly use antiseze on the plug and watch the torque

[BLADE]

Is there a foreign object in that cylinder ???

[bszopi]

Ended up tearing it all the way down, and will be taking both heads to the machine shop tomorrow to get worked on. It appears that the spark plug in #2 wasn't the only thing potentially leaking. Had a broken exhaust stud there was well, and its inside the head, so I'll get to give the machine shop even more money....

[Tbay99Venture]

Hate to post something that may already be obvious, but just in case...

You'll probably find the cylinder numbers cast in the LIM have the odd cylinders to the front of the vehicle, contrary to the way the spark wires actually go.

[bszopi]

Yeah, I know, as it indicates the intake port, which cross over the engine.

Anyway, just got a call from the machine shop. He extracted the broken exhaust stud, repaired the spark plug hole, and replaced the valve seals. He also checked for flatness and he was really suprised to find them perfectly flat. He said he almost always has to mill down 60V6 heads to get them flat. Checked them all out overall, and says I should be good to go. Doesn't look like I'll get them picked up today, but definitely tomorrow.

Now I need to plan for everything else I need/want to replace while I'm in there. Things like the timing chain (137k on the engine, might as well), O2 sensor, plugs again, thermostat... Anyone else have any recommendations for parts to replace while I have it torn down?

[Tbay99Venture]

Now I need to plan for everything else I need/want to replace while I'm in there. Things like the timing chain (137k on the engine, might as well), O2 sensor, plugs again, thermostat... Anyone else have any recommendations for parts to replace while I have it torn down?

Not on the engine per se, but if you have the rear climate control option there's no better time to reach the heater hoses & tees. The forward heater core has an oversize diameter tube and a regular size one. Might want to make sure the plastic shift cable socket isn't about to wear out as well. What did you decide about the crank sensor wires?