...Well, after Funky Si's starting woes last week, it seems we have another seemingly trouble free Zed, deciding to play games.

 

After a successful Coventry trip over the weekend, I used the Zed for work on Monday, as I could not be arsed to move the cars around when we got home. Again, no issues, all was well - and I put the Zed back in the garage Monday evening. I was visiting one of our sites on Tuesday morning, so thought it best to use the SLK. However when I got home Tuesday afternoon, I spotted a wet patch under the garage door - I opened the door and saw the Zed had dumped all its coolant on the garage floor overnight.

 

I can't see where it had leaked from, the pools are front right and rear centre - although the rear centre looks like the coolant has just run down the undertray and dripped from there. Most likely it's front right; possibly a hose failure.

 

I had no overheating issues beforehand and there was no sign of leakage whilst parked on the drive, when moving the cars around. I did, however, fit a new 1.3 bar Z1 radiator cap on Saturday. Could the increased pressure have caused an old hose to pop?

 

I filled the radiator and run the engine for a while - topping up as the coolant level dropped. It leaked some more for a while but has since stopped. I checked again today, and the radiator was still full.

 

Any ideas would be gratefully received. I could pop the car down to my local garage for them to take a look - but if it's something more serious or ZX-technical, I would certainly be best getting the RAC to deliver it to Jimmer.

 

Thanks,

 

Richard:sad:

Visual checks? Was it leaking from the drainplug at the bottom, have you looked see see if any joints are wet etc.

I would suspect the increased pressure from the rad cap has caused a hose that was on its way out or damage on the radiator to let go. I would personally stick with the stock cap which is around a fiver from Nissan, but for now I think your only option is to get the car up to temp and try to trace the leak.

Visual checks? Was it leaking from the drainplug at the bottom, have you looked see see if any joints are wet etc.

 

Hard to say Ali - the undertray is completely intact; and I'm not really able to remove it in the confines of my garage. There is some evidence of wetness on the undertray, front right, near the bottom hose, between the radiator and engine. That's from shining a torch down the front of the engine bay....

I would suspect the increased pressure from the rad cap has caused a hose that was on its way out or damage on the radiator to let go. I would personally stick with the stock cap which is around a fiver from Nissan, but for now I think your only option is to get the car up to temp and try to trace the leak.

 

Possibly; we do hear stories of this happening. Plus the weather was pretty hot over the weekend....!

 

I have a good stock rad-cap, I just thought I'd try the Z1 item to see if it made a difference. Sadly not quite the difference I was hoping for, it would seem:oops:

Hard to say Ali - the undertray is completely intact; and I'm not really able to remove it in the confines of my garage. There is some evidence of wetness on the undertray, front right, near the bottom hose, between the radiator and engine. That's from shining a torch down the front of the engine bay....

There is a hole in the undertray by the drain plug (bottom right corner of rad), but as you say, difficult to access the rest of the hoses if you have a fan shroud.

When Simon, Andrew and I went on our France road trip, mine developed a coolant leak, which subsequently turned into an even bigger leak once we repaired/stopped the first leak! We noticed that there was a significant difference between the water pressure in the hoses between our cars and mine were quite hard to squeeze due to the pressure. I replaced the stock cap for a new one and it returned to normal so I suspect the cap had failed. With the cap being the only thing you have replaced and how recent it was, it's possible that it could be faulty too but I think it's most likely solely caused by the increase of pressure in the system finding its way out of a weak spot.

 

On the bright side, it's fortunate that you discovered it when you did and not having to pull over on a long run when you get the reliable "steam pouring out from your bonnet" overheat indication!

Edited July 20, 20168 yr by Joely P

There is a hole in the undertray by the drain plug (bottom right corner of rad), but as you say, difficult to access the rest of the hoses if you have a fan shroud.

 

You're right mate, there is indeed - but I can't remember if the leakage is dripping through there! I'll have to take another look tomorrow!

When Simon, Andrew and I went on our France road trip, mine developed a coolant leak, which subsequently turned into an even bigger leak once we repaired/stopped the first leak! We noticed that there was a significant difference between the water pressure in the hoses between our cars and mine were quite hard to squeeze due to the pressure. I replaced the stock cap for a new one and it returned to normal so I suspect the cap had failed. With the cap being the only thing you have replaced and how recent it was, it's possible that it could be faulty too but I think it's most likely solely caused by the increase of pressure in the system finding its way out of a weak spot.

 

On the bright side, it's fortunate that you discovered it when you did and not having to pull over on a long run when you get the reliable "steam pouring out from your bonnet" overheat indication!

 

Interesting..... Mine were previously quite hard (ooer missus) with the relatively new OEM cap. When I got home after Coventry, all the while with the new Z1 cap in place, I noticed the hoses were not so hard. Despite the high ambient temperatures and the car having been driven at high speed for almost 100 miles!

Must be a split hose Rich.

Just a thought..... were you running the Air Con and got a big ice build up that melted onto the floor ?

You dont need an uprated rad cap Richard as it plays games with these cooling systems and upsets the balance of nature and science:huh:...Genuine nissan cap and iff its very hot and lifts then coolant straight into overflow bottle and fully recoverd and put back in the rad by syphonic magic every night or a cool down session..Thats how it should work,the cap lifts before hoses split:winkiss:

Just a thought..... were you running the Air Con and got a big ice build up that melted onto the floor ?

 

LOL....! I was running the AC Tony - but it's definitely coolant mate! The smell of antifreeze was a giveaway..... And the radiator was empty:wink:

You dont need an uprated rad cap Richard as it plays games with these cooling systems and upsets the balance of nature and science:huh:...Genuine nissan cap and iff its very hot and lifts then coolant straight into overflow bottle and fully recoverd and put back in the rad by syphonic magic every night or a cool down session..Thats how it should work,the cap lifts before hoses split:winkiss:

 

It's certainly no coincidence then, that this happened after fitting the uprated 'cap! I should have known better as everything was in balance before....:oops:

It's certainly no coincidence then, that this happened after fitting the uprated 'cap! I should have known better as everything was in balance before....:oops:

 

"If it a'int broke, dont fix it" :lol:

 

I hope it gets sorted though! Nothing worse than looking at a broken Z :(

So if you have waterless coolant, there will be no pressure and it doesn't matter what rad cap you have. Hence no hoses to split under pressure. Just a thought ....

So if you have waterless coolant, there will be no pressure and it doesn't matter what rad cap you have. Hence no hoses to split under pressure. Just a thought ....

 

It would be interesting to hear from anybody who has this done. The you tube video's look good.

It would be interesting to hear from anybody who has this done. The you tube video's look good.

 

We have just recently switched to Evans coolant in my mates extreme power 240Z now doing some Time attack rounds.

Initial results have been good.

We are using it to cure a problem at the back of the long in line 6 cyl L28 engine.

Under extreme pressure we had micro boiling which when pushed really hard resulted in several litres of coolant being pushed out in a 20 min track session. It has reduced it dramatically from 3 to 4 litres blowing out down to 500 to 600ml.

We are modifying the hose set up now to eliminate the remaining top hose air pocket, once that is done there should be no fluid blow at all.

 

At over £150 for the kit it is expensive for normal road cars and probably not neccessary.IMO

So if you have waterless coolant, there will be no pressure and it doesn't matter what rad cap you have. Hence no hoses to split under pressure. Just a thought ....

 

Good point Andy! I have seen the Evans adverts - but so far have resisted......

Im looking into the waterless coolant myself seems to make a lot of sense to me i know its a bit on the expensive side but the benefits seem worth it to me.