Is this oil or something else from the coolant system in the reservoir? The coolant tank is brand new. This accumulated over 300 miles...

 

If the stuff is oil, you should be able to see it in the radiator. I also wonder why the reservoir fill neck is discolored yellow.

 

It sure looks like oil. Like Dennis said, if it is oil you should see it floating at the top of the radiator. Just don't open it when it's hot.

Also, open the oil cap and see if there's moisture there or if the oil looks milky.

 

It's an ebay resevoire, thats prob why it's yellow. Got it for 17$. My master mechanic friend says its not oil, but crud from the cooling system. He said the coolant would be milky if it was a bad head gasket. Anyways I asked the shop to look at the coolant as well.. I will look in radiator and oil cap once i get the car back.

Why would a car blow 3 head gaskets in a row.. like wtf... this engine is remanufactured, its basically new with 40,000k miles now....

 

Three head gaskets is a lot. These motors aren't known for blowing head gaskets unless there's some specific issue like blocked cats or overheating.

My guess would be that the cats are clogged or they're replacing the gaskets without checking that the heads aren't warped.

 

What a nightmare. I do get a P0420 code for front precat.... just been resetting the light and it stays off for about 12,000k miles. My engine did overheat 1 time when giving it gas at idle. There was some air left in the cooling system that I think had something to do with it. Now I hear no more air or water moving.. but I think it's too late..

 

I was just reading through this old thread and found an easy test for clogged exhaust.
Start around post # 175 and read from there.
https://maxima.org/forums/5th-genera...ts-help-5.html

A clogged exhaust can cause all sorts of codes or no codes at all. There's no specific sensor for it. There will usually be other symptoms too. It's just an idea right now but worth testing to rule out.

If it blew due to overheating, it probably warped the heads. They really need to be sent to a machine shop when that happens to be measured properly. Hopefully the shop figured it out the second time around and got it right. If so, these should be fine.

The crud in the reservoir could just be residual from the previous blown head gaskets. That would be expected if the system was contaminated with oil before.

 

Thanks for the replies. I doubt my exhaust is clogged, i have an exhaust leak at the flex pipe. The car is pretty loud so im guessing thats not it? I also have the rear resonator removed. Had it cut off lol. Could still be cat maybe idk tho. Hoping the gunk in coolant is from old engines. I have a new remanufactured engine, new radiator and new coolant resevoire. .

 

I'm sure they reused some of the metal water lines. There will also be residue in the heater core so a little residue is to be expected.

 

Mechanic said all my fluids are good. He said I have a coolant leak at the oil cooler.

Power steering return line is also leaking..