Hi thanks in advance, this weekend I bought a 2001 Monte Carlo ss with 140,000 on it really nice looking car ,only problem is I can't figure out why it won't start here's what's going on, I've coverd all the bases I can think of all cylinders have spark,injector pulse and fuel pressure they all have good compression ranging from 185 to 210 but this thing dosnt want to run when I it turns over it will pop out of the intake and exhaust like its out of time?? I've replaced the cam and crank sensor and swapped ignition control module with a known good one plugs and wires are also brand new with new fuel pressure regulator? Only other hint is that there is a coolant puddle on top of my intake that makes me think maby intake gaskets but I would think it would still start with bad gaskets. Also guy I got it from says one day I team and the next it did this. Help I'm stumped

 

Have you checked for any codes in the computer?

Since you mention signs of a coolant leak, pressure test the cooling system.
Depending on the source of your leak or if you have multiple leaks, you may have coolant that got into the intake and into the cylinder. The plastic upper intake has a couple weak spots (specifically around the EGR stove pipe).
If too much coolant has gotten into the system, you have a situation known as HydroLock. You will need to suck out most/all the coolant from the cylinders and hope no further damage was done.
Once the car starts/runs, if this was the case, do a fresh oil change on it too.

Keep in mind, this is a possible situation, does not mean that is what you have going on. But I believe it's best to start inspecting issues that you see right in front of you.

 

Thanks for the fast reply I pressure checked the cooling system there is a small leak by the middle rear of the intake that's not too bad the car dosnt throw any codes I have it back together now after doing the compression check and there was no evidence of coolant in any of the cylinders or oil The car keeps acting like it is out of time when I crank it try's to start sometimes and puffs out of the intake

 

If it turns over but pops through the intake looks like a timing issue. Like in the OLD days when you kept turning the distributor until you found the spot but yes I know there is no distributor on this engine


A little bit of coolant should not stop the engine from firing up.


Are you sure cam went in exactly correct, re check spark plug wiring to proper plugs maybe crossed up?






Have you tried a little shot of starting fluid?? I know people are scared of starting fluid but just don't douse it.

 

I just noticed, you said you swapped the Crank Position sensor? Did this no-start condition exist before changing that sensor?
When you change that sensor, I believe you need to perform a crank position re-learn (which requires a GM Tech 2 scan tool).

 

Ok I think I've figured out what the issue is I took off the upper intake and it was full of coolant so I believe what was happening is when I was cranking it was sucking in more coolant than gas causing the no start condition and fouling the plugs out this makes sense right? I also found the seals on the upper plenum were shot and the coolant passage was degraded to the point if crumbling which would be the source of the coolant I'm going to order a new upper plenum and change the lower intake gaskets and flush the engine while I'm at it hopefully this fixes it

 

Wow that was ugly, especially just getting the Monte. Congrats on the perseverance and getting this problem put to bed before it became a major headache.