Car wont run after driving through water

Tiny
PATJ2466
  • MEMBER
  • 2005 CHEVROLET COBALT
  • 2.0L
  • 4 CYL
  • FWD
  • MANUAL
  • 144,000 MILES
My car is super charged and I drove it through water. The car died and has not restarted since. I removed plugs and blew air down in cylinders but no water. Oil looks milky though. Checked all four coils and they are fine. Replaced spark plugs. Car tries to start but is only firing on two cylinders, left to right cylinders two and three only ones firing. No ignition module on this model. I moved one and four coils to two and three positions and two and three cylinders still only ones firing. Removing air cleaner did not help. Unplugged every wiring connection I could find and inspected, also sprayed with contact cleaner, please help thanks!
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Thursday, December 1st, 2016 AT 7:27 PM

33 Replies

Tiny
STEVE W.
  • EXPERT
Milky oil suggests it ate some water. Not good, usually it means the engine needs major repair or replacement as water does not compress. First change the oil (use whatever cheap oil that matches the weight called for, you may be working on a dead engine so no reason to put $50.00 oil in it) but you also do not want to keep circulating water through it.
Stick a spark tester on one and four to see if they are actually generating a spark or not.

Then run a compression test and see what you have in each cylinder. You want all four to be within the same range (175psi in each would be good 160 will work) I am going to guess they will not be in spec. (Hope I am wrong) If they are not run a leak down test and see where the leakage is.

As for the possible problems - bent con. Rods, holed/cracked pistons, holed/cracked head, blown head gasket.
Good luck, post back with results of tests.
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Friday, December 2nd, 2016 AT 5:05 AM
Tiny
PATJ2466
  • MEMBER
Did a compression test, looking at engine from under hood, left to right #1 150# #2 165#. #3 180. #4 120 it's really trying to start just won't. Havnt changed oil yet. Turns over good. Gonna check wire loom that connects to each coil this wknd. Noticed from trying to start only #1 cylinder fowling plug.
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Friday, December 2nd, 2016 AT 8:12 PM
Tiny
KEN
  • ADMIN
Hey Pat,

This might sound crazy but have you changed the air filter. If it is soaked with water the engine will have a hard time starting.

Please let us know what you find so it will help others.

Best, Ken
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Sunday, December 4th, 2016 AT 1:27 PM
Tiny
PATJ2466
  • MEMBER
The air filter was pretty bad shape but we took it off weeks ago, didn't help. Did an ohm test on wire loom from coil packs to plastic connector not sure if anything is wrong with it or not. Really stumped any ideas would be great duly appreciated.
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Sunday, December 4th, 2016 AT 5:08 PM
Tiny
STEVE W.
  • EXPERT
OK how about a simple test to see if it's fuel or spark related. Get a can of starting fluid and give it a couple sprays and see if it fires on all 4 that way. If it does you have a fuel problem. If not it's ignition related.

Also unplug the MAF and see if water damaged it.

#1 fouling could mean you have a seal leak in the blower.

One other. Is the check engine light on?
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Monday, December 5th, 2016 AT 7:15 AM
Tiny
PATJ2466
  • MEMBER
No check engine light, had all plugs out and turned over and vaporized gas blows up out of all cylinders. Pretty sure it's ignition related.
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Monday, December 5th, 2016 AT 1:04 PM
Tiny
STEVE W.
  • EXPERT
If you are actually seeing gas then it's dumping a lot of fuel, flooding it out. Unplug the MAF and hold the throttle wide open and see if the clear flood mode lets it fire.
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Monday, December 5th, 2016 AT 3:24 PM
Tiny
PATJ2466
  • MEMBER
I will try that tonight and let u know. Fingers crossed!
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Friday, December 9th, 2016 AT 9:18 AM
Tiny
PATJ2466
  • MEMBER
I unhooked maf sensor turned over with gas pedal pressed. Still no start. I did turn key on and and checked voltage at the plug in for each coil pack. All 4 plugs tested 12.4 volts. But still no fire from 1 and 4 spark plugs I put a code reader on but no codes, I did have battery unhooked so probably why no codes.
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Sunday, December 11th, 2016 AT 6:34 PM
Tiny
KEN
  • ADMIN
Hey Pat,

It sound slike it might be a shorted coil either on 1 or 4 becasue they are related. Here is a wiring diagram to help fix the problem.

Try unplugging one or the other to see if the park will come back.

Please let us know happens so it will help others.

Best, Ken
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Monday, December 12th, 2016 AT 9:46 AM
Tiny
PATJ2466
  • MEMBER
I did move good coil2 and 3 to 1 and 4 spot& 1 and 4 to 2 and 3 spot. Still only got spark from 2 and 3. But I'll try what u said. Need all the help I can get! Thanks
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Monday, December 12th, 2016 AT 6:01 PM
Tiny
KEN
  • ADMIN
Please run some tests and get back to us so we can continue helping you.

Best, Ken
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Tuesday, December 13th, 2016 AT 10:29 AM
Tiny
PATJ2466
  • MEMBER
What about crank sensor? Could that be the issue?
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Tuesday, December 13th, 2016 AT 6:47 PM
Tiny
KEN
  • ADMIN
That could be because if the sensor is weak it would only fire every other time which would make, sense. Let's give it a try and let me know.

You could test the sensor if you have an oscilloscope.
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Wednesday, December 14th, 2016 AT 9:48 AM
Tiny
STEVE W.
  • EXPERT
As many crank sensors as I replace they need to make a tester just for them. O-scope works but not a cheap DIY item.
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Wednesday, December 14th, 2016 AT 11:01 AM
Tiny
PATJ2466
  • MEMBER
Oky men its been a few days but I did put a new crank sensor in, car WILL start and idle slow for a couple seconds then spits and sputters then dies. The few seconds it is running I press on gas and it dies, will only idle couple seconds if I dont press on gas and die. But it now is kicking out a code, P2228 barametric pressure circuit low. MAP sensor possably? I went to a parts store they say I have a bent piston or cracked piston head. Hope thats not the case. I think were getting close! I changed oil too. Was milky brown in colar. Deffanetly had water go through it
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Friday, December 23rd, 2016 AT 3:37 PM
Tiny
KEN
  • ADMIN
Hey Pat,

Milky is not good, you may have a blown head gasket, can you remove the spark plugs and check their condition to see if any are discolored from the rest? also here is a guide to check for a blown head gasket.

https://www.2carpros.com/articles/head-gasket-blown-test

Please let us know what you find so it will help others.

Best, Ken

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Wednesday, December 28th, 2016 AT 12:33 PM
Tiny
PATJ2466
  • MEMBER
Oil was milky from sucking water in from intake. Did compression test all 4 cylinders were 120 and higher.
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Wednesday, December 28th, 2016 AT 7:21 PM
Tiny
KEN
  • ADMIN
Okay the compression seems okay, lets continue with to see if you missing spark or fuel pressure?

Here are some guides to help you

https://www.2carpros.com/articles/how-to-test-an-ignition-system

and

https://www.2carpros.com/articles/how-to-check-fuel-system-pressure-and-regulator

Let me know what you find

Best, Ken
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Wednesday, December 28th, 2016 AT 7:54 PM
Tiny
STEVE W.
  • EXPERT
BAP sensor is a different part than MAP on that engine. BAP measures pressure outside the engine it's on the top left near the MAF sensor. MAP is inside manifold pressure and is stuck in the manifold farther back. From the setting criteria for that code I would replace the BAP sensor. You could check it for 5 volt and ground but I suspect those are OK.

Now that it does try to start, try unplugging the MAF and see if it sets a code, it should if the PCM is seeing it.
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Wednesday, December 28th, 2016 AT 10:16 PM

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