99BlackPonyGT

when my intake cracked and dump coolant into my plug wells, i had 2 COPs get fried...that could be the reason you have a miss still...check out your COPs and see if they are in working order

705techno

Any easy way to do this? or just buy a new one and swap until I find the sweet spot?

99BlackPonyGT

i would take it to a dealership and have it scanned to find out which cylinders are misfiring... i think they charged me $79 for the diagnostic

WhiteFoxGT

Yea I would suggest getting a dealer to run a powerbalance test... or check mode6 on the scanner. It will tell you which cylinder is dropping off/missing. Most likely a COP or 2 going bad. If thats the case I recommend replacing the faulty ones and all the spark plugs. When you swapped the intake did you yank the plugs and spin the motor over to clear the cylinders of coolant before you attempted to fire it up?

705techno

I did the plugs prior to the manifold, I never thought of clearing out the coolant before running it, maybe I fouled the new plug already! I guess that will be the first thing I will check tomorrow.

If the coolant in the wells did kill the COP, at least I know which one to start with!

GT Tommy

When you removed your intake manifold, did it look like this? This picture is of my son's 2003 GT Mustang. You would not believe how many people are experiencing the same exact coolant leak. This is why the coolant got in your driver side spark plug wells. Your coolant leak was around the base of your thermostat housing. Here's my opinion of what is causing this to happen. First of all, I believe there is a design flaw, in this area where the coolant leaks. The plastic material around the thermostat coolant port base, is only 1/4" thick. Now, when your thermostat gets stuck or frozen, it does not open. All that hot coolant and pressure needs to find a means to escape. So it looks for the weak link in the system. That weak link happens to be the base of the thermostat housing. Because the plastic material is only 1/4" thick, it deforms and in some cases melts, allowing the "O" ring to move out of position causing the coolant to leak. Personally, I think that the stock thermostat runs the engine too hot. Over a period of time, the thermostat starts to freeze up or get stuck. This is where the overheating problems all start. With that said, we now run a 180 degree thermostat. So, far we have no overheating problems. You can check on all of my post concerning coolant leaks, you will see that they all lead to this intake design flaw and over rated thermostat. I can tell you that there are many. We did replace this intake with the Dorman PI integraded type intake. So far so good. We don't intend to keep the car too much longer, otherwise we would have gone with one of the aluminum intakes on the market. My son is waiting for the new Chevy Camaro to come out. For us in Hawaii, the new cars come out in September. When you replaced your intake, did you change your engine oil and oil filter. I sure that when you removed your spark plugs, coolant got into your cylinders, unless you sucked all the coolant out of the spark plug wells before you removed your plugs. If you did not suck out all of the coolant and it did end up in your engine oil, this is what may be fouling your plugs. If this is the case, you need to change your engine oil and oil filter. Before I removed our spark plugs, I used a wet and dry vac. I install the narrowest vac attachment and placed a straw in it then used electrical tape and tapped it real good so air could not get sucked in. It worked like a charm. All the coolant and rubbish got sucked out. Hope this hepls! Good luck, Tommy.

reznap

I think the danger in not clearing the coolant out of the cylinders would be the chance of hydrolocking the engine on the compression cycle and breaking the engine internals (usually rods). If it was only a little it would get blown out the exhaust and wouldn't be messing up the plugs.

What whitefox was saying, I did with a detroit diesel and it shot coolant all over the ceiling of the shop like old faithful.

705, let us know how the diagnosis turns out, I have extra coil packs (I changed mine to accel and didn't really need to) that I could get to you cheap.

rthouck

I'll go ahead and echo what everyone else said just cause I read your post - check the plugs - its easy and worth it - change the oil, either has coolant in it or is just plain neglected like the rest of the car could be - and then check the COP. I predict those steps will solve your problems!

WhiteFoxGT

What are your predictions on this week's lottery numbers?

705techno

Just wanted to pop back in here and say thanks for all the advice.

After limping my pony home that initial day with the "man what have I bought" thoughts it turned out wonderfully basically because of the advice posted here.

Probably the first time I have bought something half dead, started throwing parts at it and fixed the problems with hardly any cash dropped at my mechanics.

I did as suggested and put on a new intake manifold, replaced one of the COP's, PCV valve and cleaned the IAC and contact points on the MAF.


It passed the etest with flying colors; Ive had it on the road since last Tuesday and absolutely love it. Its idling perfect, has great power throughout the RPM's and isn't burning or smoking anything. Still some bugs to work out but thats natural for a car with 250 KM (140miles) on it that has been neglected. I don't think I have four grand in it yet and the best part is the wife likes it. Guess that means I can keep it? ha!


Thanks again guys!