GQ coolant leak, but from where??

[gone bush SA]

hi, wanting to pick your brains, we have a GQ '91 patrol, 4.2 petrol carby model, well there is a very slight leak of coolant that seems to be coming from a spot we can't see, it looks like it's coming from under the manifold in front of the oil filter (may be a heater hose?), we have tried seeing what's there from on top, underneath, but just can't see exactly where it's coming from, does anyone know what's there, what's it's made of and how is it attatched ie- srewed in or plug etc., and what the best way to get to it, don't really want to stip off the manifold to get to it if it can be helped, thanks for any help
chris

[growler2058]

Gday Chris welcome aboard mate gotta friendly mob here fulla great info and advice. Jump over to the intro thread when ya get a chance an say gday and youll get more responses

[jc58nc]

When you park the Patrol at night tuck a sheet of newspaper under the manifold and look for the coolant green stains in the morning. Hope it helps track your leak.

[gone bush SA]

we noticed a small bit of thick coolant under the car after sitting, and on closer inspection we found a staligmight of coolant, but try as i might i can not see/ get to the spot, it seems that it is coming from under the manifold, but i'm not sure what the fitting that goes into the motor is made from or how it atttaches and is there any good and easier way to get there without pulling all the maninfolds etc off. as i can't get there from under the motor because the diff is in the way and from above i can't get there either and my arms aren't the longest either.
chris

[pearcey]

Use a mirror mate shine a light under the manifold a check with a mirror.
You may have to juggle it a bit but you should be able to see offending part.

[gone bush SA]

i tried a mirror but can't get there to see

[Robo]

Have a look with mirror in top right corner behind alternator there's a pipe that screws in there.
This takes coolant to dual pipe fitting bottom centre of inlet manifold, good chance this pipe or hose is your problem.
Replaced pipe on wife's car about a year ago genuine item $22, I think it was.
The 2 way fitting was a Shock think they quoted me $80.
I cleaned $80 one up and re-zinc plated it myself, I have a small plating kit, works well, bit of fiddly work, but I enjoy the challenge.

The only tip I can suggest if $ are a problem is.
Providing metal fitting is still fairly sound, but leak due to a bit of external corrosion (not rusted through) you can clean the fitting up, remove rust and solder fill corroded area.
This process of repair can be ok, BUT depends alot on the individuals skills, so consider it a temp repair.

Plating is really, a read instructions and talk with supplier, then hands on learnt process that's to hard to explain just in writing. sorry no help here on plating it's really a learn from experience thing I recon.

Cheers

[gone bush SA]

ok, we have found where the water was coming from we have now taken the manifold off, it's a plate that is at the rear of the motor that makes like a water jacket, there was no gasket left on it, the strange thing is that under the plate there is 3 welsh plugs, but we can't workout why there is welsh plugs inside a water jacket, there is also 4 other holes that don't have welsh plugs in the same jacket. so we are wondering why would we worry about changing these welsh plugs when they don't seem to do anything and does anyone know the right size for the welsh plugs so we can order some in, thanks

[Robo]

Your talking about the cover plate that is bolted to the block a few millimetres above oil filter position.
If so nissan fast is quoting part No 00933-1351A .
plug designated letter " J " on schematic .
plate is where oil cooler goes.
but as the part number could of been changed it's best to check with nissan when ordering.

[Silver]

While you've got the manifold off, I suggest you consider replacing the rubber coolant hoses that run along under the manifold as well - they are hard to get to with everything in place :-)

[gone bush SA]

hi again, does that plate (as above) have a gasket on it, as ours ddn't but by the look of it and as it's to hold water in you would think it should, thanks heaps for all the help so far

[gq4200]

Silastic Gaskets will do that plate .. or Loctite 5900.. I have used.

[Robo]

Nissan fast show silicon for 4.2 petrol and gasket for diesel version with oil cooler fitted.
silicon for your 4.2 petrol one.
Think oil coolers on a petrol model, was for middle eastern version of MQ, MK and GQ .
if your thinking cooler, It might be hard to find 1 localy, maybe ex Japan. Bet it's expensive .

[advarp]

hi again, does that plate (as above) have a gasket on it, as ours ddn't but by the look of it and as it's to hold water in you would think it should, thanks heaps for all the help so far

No gasket on that. I have replaced that plate twice in 5 years, first one was corroded badly, second one starting to - although of crs I use good quality coolant and flushed the engine etc. When taking the second plate off, there was some rust-like muck (perhaps just mud from dust?) at the back of that cavity. I don't like what I see :-/ and I take good care of this truck, seldom offroad and never deep creek crossings. No muck anywhere else. Anyway, it's a good thing you can give that area a wash with a hose (flush through to the drain bolt hole and to the radiator etc before you put it all back. Always bought a new plate.

on my TB42S, to take the plate off you only need to 1) drain the coolant and 2) take the oil filter off - a small amount of oil will leak but you wont even need to top it off - check the dipstick after all is back in.

First time I used the blue expensive sealant stuff you buy at SuperCheap / Autobarn etc, second time I have had black Toyota genuine sealant for their oil sump / pump left from a Toyota job. I bet this will hold a lot better.

You know - I always wondered why the... would they put yet another plate there - just to have another fail point? Now it;s clear :-)