So.... Drove the car the on the weekend and noticed the temp gauge rise so pulled over and noticed it was leaking coolant....great!!!! Popped the bonnet and couldn't see anything obvious, let it cool down topped it up and drove home. Could see dripping from under car but couldn't pin point it. Checked levels next morning and they were fine. Checked levels next day and they were fine again Drove girlfriend to work and noticed the temp needle rise again. Pulled over and again dripping from under the car. Topped up and drove to work. Drove a couple of k's at work and noticed every time I parked there was a small puddle under the car. So after work tonight I set about trying to find the problem. CAN"T FIND WHERE THE LEAK IS COMING FROM Initial thoughts were the 'bastard' hose as I have done a plenum pull and water bypass. I also have heater matrix bypass aswell. So lifted up the car got underneath and saw drips from the passenger side. Right "bastard hose it is them. Shone a torch up and there was no water from the turbo water hose. THe drips were from the air con drain. Phew!!! Might not be the bastard hose. Further investigation found the water was actually dripping down from the drivers side turbo but not the side with the water lines. Unfortunately the water is dripping through a hole between the gearbox and the engine. Its just a hole on the back of the sump. So something is running down from above. I can't for the life of me find where its dripping. I had a good look round the where the heater hoses are and too off the bypass to get a better look beneath but the hoses were all dry. Getting annoyed and with light fading I put the car back together and topped up the coolant with the engine raised 2 feet in the air. Ran the car for a good 10 minutes and...... NO BLOODY LEAKS!!!! Totally stumped Will try and find pictures to help pin point area. Any ideas? Sorry for long post.
You need to pressure test the system, that will help you find the leak. It's also easier to find if you have the bright green coolant.
I know I need a pressure tester, just can think where it would be coming from unless its one of the heater hard pipes Its dripping next to the oil filter. Beavis
It's like playing "Where's Wally?" or solving a murder mystery, pin-pointing a leak on these lovely lovely cars East Coast Z is right, pump the system up to around 17 psi and get busy with one of those little telescopic mirrors or a drain camera. You can even wrap tissues or dunny paper around a length of wire and go probing You don't need a proper pressure tester, just use an air compressor with the regulator turned way down. Start with the regulator too low and bring it up gradually. Disconnect the overflow hose and put a short length of hose on that spigot on the filler neck, pump it up via there with a blower nozzle. Here's a pic. It shows a pressure gauge teed into the line but that's not necessary if you keep a careful eye on your air compressor's gauge. Good luck dude
So where exactly is it leaking from? Down and out the hole at the bottom of the gearbox bellhousing, or around the oil filter, or both? My guess would be the heater hose even if it's been bypassed or possibly one of the bypass hoses (how long ago was it done? Could also possibly be where the heater hose hardpipes attach at the back of the engine where they use gasket goo to seal them on to the pipe that runs to the waterpump. Could also be a leaking welsh plug or two?
also possible a welch plug or 2 have gone. if 1 is gone replace them all, they cost around $1 each IIRC there is 11 or 12 of them,
Please be careful pressure testing you systems if you haven't done it before. I cracked the top of my 1990 JDM NA radiator just flushing it with the garden hose. But then again I'm a friggen spazzo. You can be spastic like me and just blow it up. Or you can start at low pressures and only build it up as necessary. At the end of the day IMO JDM OE rad is POS anyway. I will be replacing it with a 3 core aluminum replacement and auxiliary tank.
The coolant hardpipes at the back of the engine have the turbo pipes T'd off there and can corrode causing leaks under pressure .
Well I don't know whats going on with my coolant system but my car has magically decided to fix itself. Just pressure tested the system to 16psi and left it for 20 minutes. Held pressure no problem.........totally confused. These cars are crazy!!!
You forgot to add 3 core aluminum replacement and auxiliary tank, for Commodores LOL. But seriously, let me know which one you go for. I have been looking at the Canadian one. $199 for the radiator, but shipping quotes have been $60 and $$$ more than the radiator, so I am still looking.
How so? I use a stock 2 core replacement for a Z32NA/J30 Nissan Maxima. Plastic tanks and all. It works perfectly regardless of outside temps and traffic,idling, AC on blah. Oh yes, i saw temps of 90deg.C once on the hottest day on record here at 42deg.C stuck in nose to tail crawl with AC blasting.....Is that bad???. It needs to be said that the stock fan shroud is in place and the viscous fan coupling works.
So WRONG.......... The OE radiator is plenty big enough even for most mildly boosted cars. Yours probably broke cause IT WAS AN OLD 20 YEAR OLD POS and the plastic went hard. I put a new radiator in my rebuilt car, FMIC 14 PSI and NEVER had an overheating issue or anything even close. Those big alloy radiatiors are HOCUM... and unnecessary.
Hey, everyone's entitled to their opinion. And I have never overheated my NA. No mods. But no other radiator I have owned is plastic. And I've flushed and cleaned plenty of radiators without damaging them. So I won't be buying another OE. Especially at the price of new. Simple as that. IMO, the only benefit of using plastic is it works out cheaper for the manufacturer and it creates a bigger market for replacements. There are a lot of Australian manufacturers competing for sales on eBay. $100-$200. Trick is to search for the size you want. Not just one advertised as being "300ZX". But as I said originally, this is my opinion. I will not buy another.
ALL normal production cars these days have a radiator with plastic tank ends. I cant think of one that doesnt. That includes Lotus, BMW, Merc, etc etc They are a wear item and do fail eventually. Usually by the time the plastic is brittle they are way past their use by date and should have been changed anyway. What pisses me off about the all alloy chinese ones off ebay is the bastards just don't fit properly and the fairings etc dont fit back on. Subsequently, people dont refit them and then bitch about overheating. BTW i have seen more chinese ones with leaking welds in the tanks than plastic end tanks failed. Its pretty painless to get a replacement plastic end tank these days.
I'll keep my mouth shut about buying anything from China. IMO the best thing to do is ask before you buy. "Does this come with warranty?" "Can you supply a receipt of warranty with purchase?" But ideally I would keep an OEM radiator to the side also. AFAIK, a good radiator shop should be able to replace these plastic parts with metal. Which I suppose could be a good "upgrade" or preventative measure for anyone. Just another example of production vs total quality engineering IMO.
