Long story short. Ok so it rained HEAVILY where I live and I came upon a street that looked flooded so I decided to do a U turn and get out. Well, it was very dark and I misjudged how high the water was during my 3 point turn and as I put in reverse the car bogs and dies. Will not crank and at the last Ignition key position all dash lights dim down.

I get towed home, etc... that was last night. Fast forward to today charged the battery and removed each spark plug and a huge amount of water spat out of cyl 4. However, the car ran fine after that. Keep in mind that since it bogged and died the TOTAL engine run time was no more than 2 minutes. Ok I decide to check the oil and it's milky . (I have a CAI with filter in front of radiator hanging very low)

I just did an oil change right now and it was ALL milky. It has fresh Mobil 1 oil. Should I just stop right now and have this looked at or should I let the engine run and pump the fresh oil through the engine? It still appears milky after running it for 5 minutes but it could be residue + shitty DE dip stick. Again, the engine has not run for more than a few minutes and the engine seems to run well.

What's the concensus here? Keep it running? I'm going to open the drain plug and see exactly what color comes out .

This is not my daily driver but I need some input fast. Of course any shop will just have me bring it in but I want some unbiased opinions.

Thanks a lot

06 rev up, 110k miles, super healthy engine, burns NO oil.

 

I drained some oil (after oil change) and it still looks milky. Although less thick than it was before but still milky.

Ran the engine for 2 minutes. Put my ear up to the engine and I don't hear any excessive noise that wasn't there before. (knocking, loud tapping, etc)

Should I drain once again? run some motor flush chemical and then drain?

 

Look up "hydrolocked engine repair".

Long and short of it is its not necessarily the end of the world - BUT, there could be severe damage, I won't sugar coat it. Water doesn't compress and enough pressure can develop to break stuff, e.g., head gaskets, valves, valve seals, piston rings, etc.

Change the oil again and bump the engine a few times with plugs out. Repeat until clear. (Just use conventional motor oil until it's all cleared up!) Get yourself a scope from Harbor Freight to give you a view of the inside of each cylinder to see if there's residual water after a few bumps.

Also keep in mind that your car took a big gulp through the intake system so there's probably water remaining in parts of the intake system. You may need to remove the plenum and/or entire intake system to clear it all out.

After that, since you have the plugs out, run a compression test (but only after you're sure you've cleared out all the water. Any trapped water is going to shoot pressures up well beyond the plus/minus few pounds of a normal engine. But this will also help point out any damage outlined above.

Hoping for the best!

 

UPDATE:

I did 3 oil changes total. 2 of them with an autozone product called MOTOR FLUSH ($5/can) and with cheap 0w-20 oil. The third was with my typical 0w-40 and I am pleased to say that the oil is looking VERY clean not a hint of yellow. I hit the nearest canyon for a short run and it seems to be ok. I checked the oil before and after and it's good as new. I will continue to monitor it since I do track some with this car and this was a big scare.

Big relief :sigh:

 

Right on ... I'd consider doing a few more very short duration oil changes as I think what mic said holds value small amounts of water in obscure places.

You may want to go one step further and send a few samples to blackstone labs for their analysis.

 

Yes i will replace the oil a couple more times coming up soon here. Also I will do a compression test just to be on the safe side. Only thing is that I haven't done one before this so I only have the optimal values for basis of comparison.

 

^yea, a compression test would be very smart...

I should have put this in my previous post, but put 3k miles on your oil before you send it off to blackstone to give them a good sample.

Interested to see how this plays out

 

You're looking for anomalies or deviations between cylinders more than absolute values. If they're within +/-10psi (or thereabouts given age), you can use this set of readings as baseline for any future troubleshooting.

But, for reference, Z motors should exhibit a new motor compression pressure of ~185psi. A 15 year old motor with miles will be lower of course so use that only as a guideline. If you're below 140 or so, you'll need to address whatever the issue is pretty quickly.

 

I plan on draining that oil where it’s at now add 5 quarts to drive it about 15 miles home. Should everything be okay for that drive then I plan on flushing it out, then doing a whole oil change.
2007 350z HR

 

this thread is 2 years old brother

 

Glad someone pointed that out before me....

Luckily most of the members in this thread are still active on here

 

I've done the same thing before except the one I replied to was about 8 years late 😂

 

I remember that. And Travlee is the one who called you out on it! 😂😂

 

lol you guys 🤣

 

2years (in reality it's like 18months) is nothing for bumping a thread ... this thread is just a little baby-thread ... see everybody in 2028 when someone else bumps it

 

Travlee will still be floating around the forums, waiting for his "dead-thread-bump" senses to tingle, while cruising the streets in his C8! 😁😁😂😂

 

Well at least he learned from the best

 

Cameron, are you saying your 1st post is about a hydro-locked motor? Sorry man!
I hope it's not your daily for obvious reasons. All plugs come out, get new if you can afford. The step nobody mentioned - attach a clear vinyl hose to a shopvac and watch how much water comes out thru each spark plug hole. New air filter and at least dissemble and dry the intake plastic. Then fresh oil and filter. Gl.

 

Probably won’t do new plugs this week probably next. I’ve had the cold airs off up to the throttle body for a couple days. I towed back to my dads garage. Can I just crank over the engine with plugs out to get the water out or shop vac a safer option ?

 

I'd definitely say shop vac is a much safer option. If anything, using a vacuum would get much more of the water out than the pistons alone