Rep Power: 0

My wife was driving our 98 civic lx back from work when it overheated and started smoking a little. She was able to make it back, but the small plastic spigot under the radiator cap had ruptured and sprayed coolant everywhere. Directly underneath that hole in the spigot was a small pool of blueish-gray sludge with the consistency of pudding. I opened the radiator drain and clean green coolant came out, but only a little. I started the car to get the thermostat to open up, so I could drain anything else that was in there, but after getting 25% up the temp gauge, the car died and would not start again, only crank. I found that the plug wires were melted onto the spark plugs. 2 hours and new plugs/wires later, the car started, but ran rough at idle, kind of like it was running with no engine mounts in place. The car was giving me a "engine coolant temp circuit low input" code with my scan tool. So, I replaced the ECT sensor and it still ran rough. I'm about to throw a new radiator in, but wanted to ask your opinion about that gray sludge I found around the radiator. If there is a 90% chance this is a blown head gasket, I'm probably not going to screw with it. If it's 50/50, I may throw in the radiator and see what happens. The car has been in my family it's entire life. I've had it for two years. I don't believe anyone put leak stop in the radiator in the past. Thanks.

 
Rep Power: 518

No coolant, melted plug wires, melted radiator neck, gelled antifreeze residue.

That's been overheated BAD. BAD BAD.

I expect a warped head at MINIMUM.

Possible (and quite likely) ring damage due to severe overheat. Normally when I see melted plastic parts, I strongly recommend complete engine replacement.

Before you commit to the radiator, you ought to investigate just how much damage there really is here. Because it needs more $$$ than just a radiator.
If the hoses crackle when you squeeze, replace them too.
Is the timing cover melted? Again, very bad.

 
Rep Power: 0

No other melting present. In fact, I pulled the valve cover off and was able to reuse the gasket when I put it back on. The plug wire boots were melted onto the plugs and took some effort to get out. However, they were just Duralast wires and I expect they don't have as much tolerance for heat as OEM. I checked the oil and it was a little low, but not milky at all. There is also no white smoke coming out of the exhaust. Hoses are a little rigid, but still okay. Again, it idles rough right now, but smooths out above 2k rpm. Anything else I should do or check before moving forward? Thanks.

 
Rep Power: 518

The evidence you present STILL screams severe overheat.

I would need to ascertain the extent of engine damage before anything else.

Will the radiator still hold water?

(If the radiator won't hold pressure, then you would need to get the water level higher than the cylinder head.)
Does water get into any cylinders?

Can you do a compression test?
Can you do a leakdown test?



Did you really empty the radiator and THEN run the engine for a while?

 
Rep Power: 0

Yes, I did.

I'm going to run up to Autozone and borrow a compression testing kit. I guess that should give me an answer on the head gasket, at least. I'll report back.

 
Rep Power: 518

This may be the cause of more problems than it started with.

You ran it until it was hot enough to quit on its own, that's really bad.





Another thought: add thermostat to your shopping list.

A compression test does not tell the entire story, it does not reveal all possible ways a head gasket can fail. A compression test only checks for compression loss, which can have several different causes.


If the head gasket (and/or warped head) is breached bad enough to show compression loss, then ring evaluation can't be done with the compression test. You may need to do a wet compression test, then possibly a leakdown test--but either might be futile if there is major head gasket leakage.


If that's the case, it's up to you to guess if the rings have been compromised, and deal with any effects of that damage later on: Low compression, oil consumption, etc. (This is why, when presented with evidence of severe overheating, engine replacement is suggested at the shop. We could do a whole lot of expensive work and the job still goes to poop after fixing only the head gasket portion.)
OTOH it could turn out ok. Nobody will know for sure until the work is done and the engine is running again.

Used engines can be found fairly cheap.



HTH

 
Rep Power: 367

you are in denial mode... sorry. melted plastic is too high temps.

 
Rep Power: 0

This is very accurate.

Okay, so it looks like I'll be replacing the radiator, hoses, thermostat, coolant, and whatever else to get it whole again. I've decided that I'll be attempting to repair this vehicle, regardless of the severity of damage, if only for the experience. I'll report back when I'm done.

 
Rep Power: 0

Well, I put in the new radiator and started the car. Again, it ran rough, but seemed to smooth out after about a minute. I noticed that I could hear a loud ticking coming from the exhaust while it was running. I brought the RPMs up to 2k and when I let off it died. It will not start now. It will likely only start now when cold, like it did yesterday. The exhaust smelled a little funny, but still no smoke. Any thoughts?

 
Rep Power: 0

Full disclosure: I mistakenly switched two of the plug wires on the distributor when replacing them. I switched them back after hearing there was a real bad miss and now the car runs as good or better than before. It was just a big coincidence that the car ran the same way with the melted plugs and the two switched plugs. Thanks for all the help.

 
Rep Power: 518

What are the results of the compression test?

Can you do a radiator pressure test now, and check if antifreeze is entering any of the cylinders?

Does the radiator fan run at spec temp?

 
Rep Power: 0

Didn't do the compression test. I filled the radiator and ran the car for a minute with the rad cap off. The fluid stayed level and didn't bubble. I used Prestone 50/50 and Water Wetter. It was in the mid-80's today. I ran the car pretty hard with the air conditioner on full blast for about 30 mins. The temp needle stayed well below the halfway mark on the gauge.

 
Rep Power: 367

hope it keeps that way...

 
Rep Power: 518

Ya know, all this probably started because of super low coolant level.

Did the original cause get found and fixed?