Cooling system overhaul, now car wont start.

Just like the title says... My expansion tank blew up and took the radiator neck out with it so i decided to just go ahead and replace the entire system. Radiator, upper and lower hoses, thermostat, water pump, expansion tank. I replaced everything and when i went to start the car it cranked for a second or two and then killed itself.

I tried holding the key and giving some gas and it sounds like it fires a cylinder once or twice then it kills itself again. I stopped trying to avoid damage. Any tips on what to check please??

Did you perhaps leave an electrical connector unplugged?

I did actually, the sensor on the lower radiator hose wasn't clipped in all the way, but still no start...

Originally Posted by SlimE46

I did actually, the sensor on the lower radiator hose wasn't clipped in all the way, but still no start...

AFAIK, that sensor won't cause a no-start condition. Are you sure you didn't unplug something else?

In the beginning, i didnt have the fan clutch tools so i tried the "hard whack" technique where you hit a big 32mm wrench with a heavy hammer to knock the fan cluch bolt loose.i tried about 8-10 times abd It didnt work do i just went and borrowed the correct tools. So technically, every time i hit that thing it was turning the motor slightly backward every time i whacked it. Could it be possible to set the timing off?

As for unplugging anything else. I really dont think so. Im looking over all the connections now and nothing seems to be loose or disconnected. Im stumped..

Maybe your battery just needs to be charged have you checked your battery voltage? You can't mess up your timing rotating the engine backwards unless your timing chain is stretched or damage.

I can't see where the hammer would knock the timing off. The timing "belt" is actually a chain, and damn near impossible (unlike a belt) to jump a tooth or two under the torque of trying to loosen a bolt.

Sorry this doesn't help you find the solution, but it should put your mind at ease.

Originally Posted by bernie21614

Maybe your battery just needs to be charged have you checked your battery voltage?

I bet it's this. Try jump starting it.

Ok thats good to know. I was told it wouldn't but i needed to be sure. I thought it was because of a low battery already so i tried jumping the car and still got the same result. When i turn the key, it sounds like its trying to catch compression a couple of times but just... Doesn't. Im running out of ideas what to check other then sensor connections?

Just got it to start! I heard some weird buzzing noise coming from my disa valve so i said what the heck and un plugged it. I turned the key and it started but only when playing with the throttle. It wont hold a idle either. I plugged the disa back in and it will now start but will stall out once the throttle is let off

***UPDATE***

Ok so after having it started i recieved a CEL. Its p0102, every website is pointing toward the MAF sensor. When the tank exploded, im assuming the hot coolant went all over the MAF and damaged it. Has this happened to anyone else? Im going to try and clean it now but any further help would be appreciated.

I also have a cold air intake, think it would have sucked up the coolant and damaged the MAF directly!? Or am i probably over thinking this

It is unlikely you damaged the MAF. Unplug the connector to it and have a look for corrosion, water, etc. Also see if your car starts in open-loop by starting it with the MAF unplugged. It should run this way, but on a conservative fuel/timing map, so I wouldn't recommend driving it.

It does the same thing, it starts, runs like crap, then shuts off. I tried cleaning the MAF with MAFs spray to no avail. The connector "looks" ok? I checked the intake boots too. No cracks?

Ok, forget the MAF. p0102 is probably from your intake. I'm inclined to agree with Mango, maybe you knocked something loose or created a vacuum leak when you did the cooling system.

Agreed, definitely a vacuum leak i cant find it anywhere though. The engine wont even stay running long enough to go listen for it or anything either. I did find this random black tube resting on top over by the cabin filter housing.. Its about the size of a straw and slightly larger in diameter...hmmm

Originally Posted by lcoleman

Ok, forget the MAF. p0102 is probably from your intake. I'm inclined to agree with Mango, maybe you knocked something loose or created a vacuum leak when you did the cooling system.

No Mango in this thread as far as I can tell. I was going to blame him, though!

Clean up connectors, clean off belts of coolant, and how could coolant get into your maf. Your air comes in from the air shroud, unless you went playing around with your perfectly good bmw and added some CAI.

I was going to guess that your therm is unplugged or you forgot to plug in the exhaust vanos solenoid...or there's another plug, past the therm.

I'm liking the missed connector theory too.

Originally Posted by SlimE46

Agreed, definitely a vacuum leak i cant find it anywhere though. The engine wont even stay running long enough to go listen for it or anything either. I did find this random black tube resting on top over by the cabin filter housing.. Its about the size of a straw and slightly larger in diameter...hmmm

Sorry, did someone else do this work for you? That sounds like a section of vacuum line. Maybe someone replaced something?

Oh, and then there are the other simple things...did you reuse belt and put it on backwards? Wrong belt routing? And, what brand components? Is your thermostat aluminum housing?

Originally Posted by SlimE46

I also have a cold air intake,

Originally Posted by dmax

Your air comes in from the air shroud, unless you went playing around with your perfectly good bmw and added some CAI.