Drove 1.9 diesel polo through puddle. It is not working as it was before

SOURCE: 1995 nissan maxima bogging

My 95 did this exactly to a Tee. After trying several things, like cleaning/replacing MAF, fuel injection cleaner to no avail, I ended up unplugging my battery overnight to reset the ECU. The next morning, I put cleaned old MAF and put it back on. Then hooked up battery. Started up, no bogging at 2000 rpms, no stalling, etc. The new MAF was an aftermarket that I bought on Ebay for $86. My car didn't like the aftermarket MAF, so I wouldn't recommend. Anyway, that was 2 weeks ago, and everything is still running good. Hope this helps.

SOURCE: Overheated car , fixed huge leak from water pump , shaking now

Hi the car would only need to overheat once to blow the head gasket,, it depends on how hot the engine got and how long you carried on driving it, you can boil the oil crack the cylinder head ect,,, check the oil for water mixing with it (common sign of head gasket failure) the oil goes like a milky colour,, but if you have already checked this then still dont rule the head gasket out,,, it can leak the other way water out of the cylinder head,,, check for any signs of dripping water around the cylinder head, white smoke from exhaust pipe ect,,
But the best way to rule it out would be to get a compression test done this wont cost much and give you a definate answer,, If it is the headgasket it aint expensive to buy the parts its the labour that cost as it aint a small job,,, if you have the manual give it a go yourself and remember you can post on here if you get stuck along the way,,
Hope this helps some
Steve

SOURCE: drove through a big puddle

if you ever **** up water and you get it shut down in time the only way to get the water out is to tear the negine compleatly down and clean everything cause if you dont wait long enough you risk ####in up your engine and it could take up to a couple months if you wait :thumbdown