black expansion tank

[user 49673]

hi all just bought my first nissan vehicle, 2007 navara d40. got a problem already lol got black oily stuff in coolant tank, had oil analysed no water at all in oil or transmission fluid, car is running sweet no overheating problems. my question is untill i hear back from last owner has something been put in coolant tank like oil or mixed wrong ant freeze or maybe its hose corrosion any ideas would be greatly appreciated its done 111,k. in radiator thers a few floaty black bits as well. is doing a complete coolant flush first port of call.

 

[Old.Tony]

You could do a complete flush. Previous owner may have cracked the head and put ChemWeld or similar in it, and not cleaned out the radiator, but let's not start there just yet (although a cracked head isn't the end of the world). It might also have had a small hole in the radiator and they used K-Seal (I've done this myself, and replaced the radiator shortly thereafter just to be sure). K-Seal is brilliant stuff but needs to be flushed out completely - this may be what's in there.

Consider the possibility of disconnecting the transmission cooler lines from the radiator completely and installing a separate transmission cooler in front (especially if you're going to be towing). Do this before the flush if you're going to do it.

 

[user 49673]

thank you tony would i have to remove old cooler or could i install in front of it any idea where i can purchase one much appeciated.

 

[user 49673]

yes will be towing horses tony would you go original cooler or aftermarket

 

[user 49673]

might just do the flush tony first and see what reappears in tank after a good run drove it home around 45 miles with no overheating and smooth gear changes

 

[Old.Tony]

That sounds promising.

The original cooler is actually inside the radiator, so there's a risk - if there's damage, or corrosion - that one will contaminate the other. And that's really, really not pretty. If you're towing horses, that's about what, 500kg of trailer and 750kg per horse = 2 tonnes total? That's significant enough to consider the external cooler.

Mine was supplied by a mechanic, he showed it to me and I approved - bloody big thing it was, can't remember the brand (this was years ago now) but I'm fairly sure he got it from Bursons Auto Parts. Mine is something like this one:

https://www.ebay.com.au/itm/1141315...io29TIeIVA%3D%3D|clp:2334524|tkp:BFBMyKW6yOhf
Since the old cooler is inside the radiator, the new one's going in front regardless. For safety's sake, you might want to block off the old cooler connections. If anyone has to work on the auto transmission, you need to remind them (more than once) that you have an external cooler!

 

[user 49673]

looks like my cooler is seprate already tony i have normal radiator and another behind it more confused now lol.

 

[user 49673]

forgot to say its automatic

 

[Old.Tony]

Manuals don't have transmission coolers and I'd guess it was auto - there are three "coolers" up front in the diesels. There's the radiator, the air conditioning condensor, and the intercooler. Radiator is obvious (and the biggest). The aircon condensor is narrow and silver and the intercooler is thick and black. The oil cooler can go at the bottom of the stack wherever it's convenient, as long as it gets some frontal air. Having it partly across the bottom of the radiator in the middle of the car guarantees that the radiator fan will also draw a small amount of air through it.

 

[user 49673]

you think i should go with the flusn n clean first and hope oil cooler is ok

 

[user 49673]

Both the 10mm pipes are leaking on to floor when cars running steady drip on both fluid in trans is still full. Probs cut ends of and new clips you think.

 

[Old.Tony]

There has to be a small amount of 'slack' for movement, as long as the hoses aren't tight you'll be ok. Yes, it's worth trying that and see if it improves things.

 

[user 49673]

could it be oil cooler leaking on top of engine maybe

 

[user 49673]

anybody know if d40 2007 auto has a engine oil cooler

 

[user 49673]

looks like engine oil cooler leaking into coolant is whats wrong

 

[Old.Tony]

There is an engine oil cooler, it lives on the vehicle right hand side on the side of the engine above the vacuum pump. Its very unlikely that it will leak into the coolant system.

Engine oil in the coolant is usually a sign that the head gasket has developed an opening between the coolant jacket and one of the oil galleys. Are you sure it's engine oil?

If there's oil right up on the top of the engine it may be coming from the PCV at the rear. There have been a couple of reports of the PCV cracking, which will allow oil to flow out. Clean the area, drive the car and check it again. It's unlikely that oil from the PCV could enter the coolant system.

 

[user 49673]

Been told engine oil cooler has a gasket prone to leaking oil into the water. Others failing altogether garage up road says he's replaced a few gaskets and oil coolers. Will get to the bottom of it to be honest it smells like an additive has been put in the expansion bottle.

 

[Old.Tony]

That's why I was wondering about a product like K-Seal. Since I've used K-Seal before (because my radiator developed a hole, and I needed to get home) I've seen what it does, and I replaced my radiator shortly afterwards - not because I used K-Seal, but because I didn't want to rely on a radiator that was obviously nearing the end of its life.

 

[MANNING]

Manuals don't have transmission coolers and I'd guess it was auto - there are three "coolers" up front in the diesels.

no doubt - curious tho - whats this guy?

passenger side of the intercooler

 

[Old.Tony]

Oh the power steering oil cooler. Easy to forget that little guy, I've never had a problem with it and nobody has ever mentioned it.