Folks, I bought an 08 from out of state and had it hauled here. So far so good.

Shot at Lowe's parking lot.


I was really trying to hear the engine on a cold start to catch any funky V8 noises, but things didn't work out with the truck driver, and I didn't get to hear that. He drove it to me at the parking lot we were meeting and it seemed fine. Sounds were OK, it felt OK to the touch and the exhaust smelled normal for an M as well. I take this chit seriously


That was cool and all.

Anyway I zip it around town and about 20 mins later I have the hood open in my driveway and engine covers off, because I'm that kind of guy.
It's an Armorall fest down there


Upon driving off after pick up, I had noticed a little bit of water sloshing under the dash, which made me want to inspect what we had going on ASAP. When the car was cool enough, I checked some of the vital fluids and all seemed good, except the coolant.
When I popped the radiator cap, I noticed some thick mess on it. I did my best to wipe it off but it needed a screwdriver to be scraped off. The reservoir was below minimum as well so I had to jump into Walmart and buy some distilled water. I keep the concentrate at home, but I hadn't restocked on the H2O since moving.
I come back home, mix up the stuff while the car cools down and I decided to remove the reservoir because it looked dirty. The bottom half inch was full of this clay-like stuff. The consistency was like peanut butter or caramel and it took quite a lot of hot water to get it loose.

Video of cap and in-reservoir shots.


I managed to get it out:


a pic after pinching at it with a paper towel


The radiator cap and filler neck also looked like they had some of it caked on there, although I know I backflowed a little bit of brownness into it when I lifted the reservoir.




And this is where the temp needle is at idle. Does it seem a little low to you guys? Every single Nissan I've driven or been in tends to rest just a notch below the mid-point of hot and cold. Anyone with an 08+ M45?

And here, I have my previous 06 for comparison but I might be tripping and they really are the same.



Some facts:
1. The heat blows hot even at idle and the car not moving
2. The coolant looks green
3. No coolant smell from the exhaust
4. The oil, at least by the dipstick, doesn't seem contaminated or milky. But this only indicates the top quart and a half, which is new oil as expected. The level is good too.
5. I bought the car from a Ford dealership. I know it's GM that used orange Dex coolant back in the day, but my Jaguar XJ8 also uses Dex, and those were the years JLR was rolling in bed with Ford. I know mixing anything with Dex is bad, but it surely wouldn't get this thick, would it?
6. The odometer indicates 132K but the engine was replaced at an Infiniti dealership about 40K miles ago, which is one of the main reasons I jumped at it. No details of what exactly happened, but I felt comfortable enough with what I know about them (Plus the carfax and bodylines didn't indicate any accidents). Once you damage an engine, especially if you throw a rod, there are possibilities of secondary damage, but I can't quite see how this would escape anybody maintaining it for this long.
7. I went over the inspection/standard service for cars they receive, and no coolant system check was mentioned. I noticed the omission, but again I know these engines to self implode before any coolant issues happen, so I didn't push on it.
8. The car came with a complimentary 6 month/ 6K mile warranty. I remember seeing something like an offer for extension, which I might go for.

What do you guys think? I'm not trying to place blame, just trying to figure out what happened so I can spend more time staring thru the windshield instead of getting a view of the underbelly of this car.

More than likely someone probably used dirty tap water or something...no other explanation really. I honestly would do a full coolant flush (as in buy like 20 1 gallon jugs of distilled water and run them ALL through the radiator with the drain bolt open).

As for the temp gauge, looks normal to me.

I sure hope so. For as well as this car has been maintained, it would sure be crappy to make such a simple mistake, but so far no issues. It's cooling what it needs to and heating what it needs to.

You are doing exactly what I would do.
Flush & refill using green AF & distilled water, and monitor.
It could be system sludge from poor coolant maintenance.

My opinion, from the pics, looks like another possibility is that someone put coolant sealing tabs into the cooling system.

http://www.jegs.com/i/ACDelco/065/10-10 ... swod1v4IXQ

If so the question is why.
It could have been a preventive measure to stop a simple nuisance leak from a hose or fitting, so I would not get alarmed as of yet until further monitoring reveals something.

Worst case scenario however, is if monitoring reveals you are experiencing external coolant loss from the overflow reservoir.
It could be the coolant is being over pressurized by engine compression, like what would happen from a bad head gasket.
Small (compression) bubbles then make their way into the radiator. Eventually these bubbles over pressurize the radiator, sending fluid to the overflow tank, where it is expelled externally as pressure continues to build within the system.

For now, let's hope all will be well with the flush & refill!

PS,
I am not endorsing Jegs or the use of coolant tabs.
I included the photo so the OP can note the color of these tabs as compared to the sludge he recovered from his overflow tank. Remarkably similar, eh?
When dissolved in the coolant, the consistency is very similar to what is seen in the OP's photos!

Holy crap man! From where I'm seated it does look exactly like those tablets would when dissolved. I'm going to buy them and dissolve them in coolant to see.

And now the why, that's gonna be fun. [EdBwoy exit from left stage, enter Sherlock Holmes from right stage] I'll look through the carfax again and also try to get the history from Infiniti and see when coolant service was done, and compare it to when the engine was replaced. I know the pros at the dealership have a lot of tools to make this job easier, but I have seen quite a few threads where people were having trouble refilling coolant, purging air etc. I can't tememebr if it was the v6 or v8 engine.

Thank you very much Steve_c.

so wait, 1 M45 is not enough for ya; you need to go out and buy another one?

the gauge is pretty much normal. i just had my M35 DE engine swapped with a 60K miles one and my gauge is in very similar position. in term of the "substance", i can't really tell what that is. I cleaned my dirty coolant reservoir before but did not get such milky substance. i would flush and monitor. you have 6months 6k miles warranty, check to see what exactly does that cover so you can have something to fall back on.

Lol, I have very few vices in this world, but Nissan products will be the death of me.
I don't have the 06 whose instrument panel is pictured anymore, but I do have an 06 parts car as well.


The warranty is for the drivetrain/all internally lubricated parts.

So far the cooling system is behaving well. After my evening drive the level in the reservoir is at max, but in the cold morning it is halfway between min and max. This is what I'd expect it to do due to expansion & contraction, but you guys should definitely tell me if I'm the only one with a living reservoir.

... After my evening drive the level in the reservoir is at max, but in the cold morning it is halfway between min and max...

It's been pretty hectic here lately to do any DIY, but I've been keeping an eye on the reservoir. This evening after work the level was over max. I can't remember this much of a variation in any of my cars before.
Could somebody do me a favor and check your coolant reservoir behavior over a day? Thanks in advance

Either way, I am considering a professional coolant system check to have that on paper then contact the selling dealership.

Could somebody do me a favor and check your coolant reservoir behavior over a day?

No? Too much to ask?

Anyway, in case in the future someone is as freaked out as I was about coolant reservoir fluctuations - it appears to be normal behavior for the VK45de. I finally had the opportunity to compare a 2003 M45 with this 2008 M45 and the coolant level in the reservoir was at half when cold and actually went over full when it was at operating temp.

I did the coolant on the 03 myself after replacing the engine so I'm comfortable with what I see. I suppose it's one of those things that I never have to pay attention to since things just fall in place when refilling coolant.

When I find time to flush the system, I'll update if anything interesting occurs.

looks fine, drives fine - just enjoy it and stop worrying

You're right. The more I know about these cars, the more stuff I find to worry about. Sometimes ignorance is bliss.

so i had an incident today with a coolant hose from the radiator to the engine; needless to say, it was not fun. anyway, i found out that my reservoir tank has the same crappy mud in it. after several rinse and wash, the tank now is clean. also i think the reason why you notice the lower coolant level in the tank is because it's feeding the radiator. I made the same mistake of not filling the radiator and just the tank, after about 1hr, my coolant is almost gone.

See, most cars generally have some dirt in the reservoir. It's not something most people clean during regular maintenance. Most times I see a cloudy mess down there, more like dust... not this caramel stuff.

What happened to your coolant hose?

i'm going out on the limb and say my mechanic forgot to put the clamp back. either that or somehow the clamp is loose and moved up toward the engine. so when the engine build up pressure, it blew the hose off from the radiator which lead to coolant leaked everywhere which lead to engine over heat that lead to me re-clamped the hose, cleaned the reservoir and refilled the radiator with new coolant. I'm just glad yesterday was a good day, spring like temperature without any rain.

Wow!Glad you caught it when you did, and I hope all is well going forward.

EdBwoy wrote: ↑

Wed Feb 01, 2017 12:44 am

...

Same exact thing happened to me today same thing on the coolant reservoir and knock.

EdBwoy wrote: ↑

Wed Feb 01, 2017 12:44 am

...

Please call me soon as possible check your PM

Any update on this? I was guessing blown head gasket.

If the question was for me; no issues to speak of on my side. When I bought the car, the engine had been replaced by a brand new dealer unit.
My conclusion is that the coolant system mud is related to the original engine failure and someone forgetting to clean the reservoir when the new engine went in.

If the question is for amgberg, all I know is that he found his engine to be blown. Metal in oil and all that. I don't know what he decided to do about it.