New Tools For Diagnosis

[Blindaviator]

Decided to pick up some new tools to diagnose problems...
Still have the cooling system pressure test kit on the way later this week...

[Blindaviator]

I am still having issues with coolant loss... Last time I tried a used coolant pressure tester from Vatozone it showed a leak... Between all these testers I hope to pinpoint the problem...

[Niti QX4]

Looks good. Sometimes it's a little expensive to buy the right tools, but they are worth it. I look at the cost of the tools versus the cost of dealer repair - a lot of times it is still less expensive to buy the tools and do the work yourself. Plus, you know the work is done the way you want it to be done.....

[EdBwoy]

That infrared camera is a Swiss army knife for diagnosis. Dragging brakes, transmission fluid changes, A/C diagnosis, checking windows & insulation in the house, body temperature etc...

Is the coolant not hitting the ground? If not, then it's either being "eaten" or dripping onto a hot component like the headers (but you'd smell it if it were external)

[Blindaviator]

That infrared camera is a Swiss army knife for diagnosis. Dragging brakes, transmission fluid changes, A/C diagnosis, checking windows & insulation in the house, body temperature etc...

Is the coolant not hitting the ground? If not, then it's either being "eaten" or dripping onto a hot component like the headers (but you'd smell it if it were external)

The only time I see it on the ground is when it pushes out the overflow resevoir (which only happens on a hot day with the A/C on)... I smell it sometimes but that could be the overflow... After a run to work today I used the thermometer on most of the engine, water hoses, radiator, etc and the only parts I could find over 180f was the exhaust... It has never heated up or shown any signs of overheating...

It shows no signs of a head gasket / crack so I am still stumped on what it could be... That is why I invested in all these tools so I could confirm or deny 100% a head gasket / crack issue...

I also picked up a good endoscope / borescope so I could look different places for leaks... Trying to see the water pump weep hole but so far I can't find it... Will have to try again in the daylight tomorrow...

This friday I am going to pickup a smallish air compressor (26 gallon) to work with the leakdown tester...

Talked to a guy at O'Reilleys the other day and he said a woman came in with a 2010 Nissan that was doing the same thing and it ended up being the water pump... So still kinda stumped on it...
If it was an old Chevy I could diagnose and fix it in no time flat but with all the "design features" Nissan has built into this thing it makes it tougher...

[Niti QX4]

If it turns out to be the water pump, maybe consider changing the timing belt while you are most of the way into the job anyway.........

[atraudes]

Your water pump is behind the timing cover and is driven by the timing chain (no belt). I'm not sure where you'd look to see if it's leaking or not, other than removing the small access panel on the timing cover. Check the FSM to see what I mean and determine which one it is.

Is it possible it's only leaking while you're driving? Have you tried running the engine for 10-15 minutes after a drive to see if you can see it dripping anywhere? I'd imagine you'd see it after parking but not necessarily.

[Blindaviator]

Your water pump is behind the timing cover and is driven by the timing chain (no belt). I'm not sure where you'd look to see if it's leaking or not, other than removing the small access panel on the timing cover. Check the FSM to see what I mean and determine which one it is.

Is it possible it's only leaking while you're driving? Have you tried running the engine for 10-15 minutes after a drive to see if you can see it dripping anywhere? I'd imagine you'd see it after parking but not necessarily.

My drive to work is 20 minutes down the highway & No drips at all...

There is supposed to be a weep hole on the side of the block just behind or above the A/C pump... Still trying to find any images of it to know what & where to look...

The lady with the 2010 Nissan also had coolant loss with no drips or obvious signs of loss... So I'm still hopeful...

[Niti QX4]

Any updates?

[Blindaviator]

I tried to do the leak down test but was never able to get it setup properly in the short amount of time I had before work... I ended up doing a compression test on several cylinders and the pressure readings are telling me the engine is simply worn out... The #1 cylinder had about 145psi and the #5 had about 120psi (didn't have time to pull the TBI and IAC to reach #3 plug)... I looked down in the cylinders with the borescope and the #1 cylinder had a good all around coating of carbon on the piston... The #5 had carbon on one side and the other side was light brown and almost cleaned off... I'm assuming that cylinder is pulling in coolant under pressure... I didn't really have the time to pull any more of the plugs on the passenger side and with what I found so far it really isn't necessary anymore...
I pretty much stopped there and decided to call it a lost cause...

I will just keep driving it for now and get a low mileage salvage engine down the road to drop into it... I thought about doing a JDM but it is too time consuming for me with my work schedule...

[Niti QX4]

Well, that stinks! I hope it goes well. Please keep us posted on your progress and good luck.

[Blindaviator]

Ok so earlier today I picked up some dye and IR light to look for coolant leaks. I just went for a 20 minute drive and I see the dye around the side and bottom of the A/C compressor and it looks like some on the bottom rear of the lower oil pan.

The leak near the A/C is obviously the water pump weep hole. Guess I will see about changing that out soonish.

The dye I see on the rear of the oil pan is what concerns me more. I don't have an inspection mirror to see the rear of the heads around the transfer tube connections. Will have to pick one up tomorrow and see if the transfer tube is leaking. It doesn't look like it is running down the rear of the block. Almost looks like it is coming from between the transmission and block mating surfaces. But it is really hard to tell from crawling underneath it without jacking it up.

[Niti QX4]

Well, that's good that you have one source of the leak found! At least that will help slow down the coolant loss...