Yeah - title is a bit goofy - here is the deal - with a bit of a back story:
1) 2002 MC - been limping along w/ a radiator leak - used 'quality' leak stop - due to finances - been doing pretty well - 2 day RT to Michigan from Maryland-NP
2) Drove to NYC this past Thursday - car started over heating a bit. Stuck in traffic for 2 hours - had to turn heater on full blast to keep temp down - - - off and on - back and forth heat-cool-heat-cool
3) Got distracted w/ traffic for a bit - temp went into red zone (flashing light & bell) - cranked up heat - brought temp down in ~ one minute
4) No real issues the rest of the trip - except for keeping the coolant level up and running the heat from time to time while in the city - pretty much normal after I got out of the city
5) No issues in travel on saturday or sunday except I noticed a little roughness just in the last 20 miles of travel
6) Then this morning right out of the box - all the sudden really rough. Wasn't sure I could even drive it - check engine light flashing - P0300 random multi-cylinder misfire - a NON-trivial exhaust leak noise and it seemed to be sucking down fuel like crazy. I drove to a meeting but then back home instead of work to try and deal with this issue.

I am going crazy - the leak could be a head gasket - there could possibly be a fuel issue - it could be a number of things or a combination of things - some related to the engine over heat idea and some not related, but the "real issue" seemed to happen so suddenly - I was not expecting it.

So, I wanted to get some experienced non-biased consideration from you heavy hitters out there just so I don't go off getting into more than I need to and proceed rationally. [BTW - ordered new radiator today]

I appreciate any help or advise you can offer.

Thanks!

 

Stop leak should never be used. You could easily gunk up something that shouldn't be gunked up.

Bigger question. 3800 or 3400 engine?

 

Thanks "Black"!
Understood, but had no choice on the stop leak - thankfully it has served fairly well for a couple of months. Have new radiator in hand now waiting for me to install. [3800 - btw]

GOOD NEWS - problem(s) solved. It was one of those rare cases where various near simultaneous symptoms actually are not related.
- found and repaired an exhaust leak - did not fix/help the problem
- found and repaired a broken vacuum line - did not help/fix the problem
- replaced the plugs - found one to be soiled significantly - did not fix the problem
- misguided - but replaced injector associated with soiled plug -(long story)- no help
- checked plug wire for fire - NO FIRE
- checked coil pack for that wire for fire from the offending terminal - NO FIRE
- replaced coil pack with spare - almost new coil pack - PROBLEM SOLVED!!

Total cost (other than lost time and gas) $5 for new exhaust gasket.
[All the rest I had on hand or was provided at no charge!]
Value of personal stress & anxiety relief - Priceless!

Truly a blessing. NOW my biggest issue is that my radio/CD/tape player - complete unit - has stopped working entirely??? I can't even turn it on. :-(