Guest Posted March 14, 2016 Share Posted March 14, 2016 Hi All, I'm hoping someone can help, as my knowledge on the matter isn't great... My 54 plate DE zed started to overheat in traffic, but would be fine at cruising speeds. Also the heating in the cabin only ever blew cold unless the revs were past about 3000rpm or cruising at above 50 for sustained periods. I took it to the local garage last week where they carried out a pressure test and chekced the gasket, both came out fine. So they proceeded to replace the thermostat and bleed and refill the entire cooling system. This seemed to work on Friday when I picked it up, no overheating, I had heat in the cabin even at idle. All was well... Then over the weekend it appeared that the heating was losing it's heat... The car didn't over heat but by the time I got to work this morning the heater was back to only blowing cold and when I checked under the bonnet the coolant level was well below minimum and there was a puddle inside the front bumper. There was also spray marks on the rocker cover and bonnet inner panel, but I couldnt tell where from. The rad cap had a little bit of water appearing to be seeping out the top of it... I've called the garage and I'm taking it back tonight.. But I'm not sure how much I trust them. Does anyone have any advice or thoughts on what this might be? I'm fearing water pump but if thats the case and the coolant wasn't flowing then surely I wouldn't have had any heat at all over the weekend? Any thoughts or advice would be much appreciated. Thanks in advance Steve Quote Link to comment Share on other sites More sharing options...
JetSet Posted March 14, 2016 Share Posted March 14, 2016 Fans have failed probably, common problem. Pete Quote Link to comment Share on other sites More sharing options...
Guest Posted March 14, 2016 Share Posted March 14, 2016 Is there a way I can check? I had a quick look at them earlier and they seem to be spinning... Quote Link to comment Share on other sites More sharing options...
Ekona Posted March 14, 2016 Share Posted March 14, 2016 Stick your fingers in, if they hurt then the fans are working Quote Link to comment Share on other sites More sharing options...
Guest Posted March 14, 2016 Share Posted March 14, 2016 Just been down and started the car, didn't stick my fingers in but the fans appear to be working fine! Would a dodgy fan result in me losing vast amounts of coolant in only about 30-40 miles this weekend? Quote Link to comment Share on other sites More sharing options...
ZMANALEX Posted March 14, 2016 Share Posted March 14, 2016 If both fans are working as they should then you probably still have air in the system. Perhaps there is a blockage so best to reverse flush the heater matrix and radiator etc. If there is a build up of pressure causing the coolant leak, then you will have to find the root cause. Radiator cap should also be looked at. Not that common for water pump failure, however I have seen the impeller blades braking off. Best to get the fan motors checked again. Perhaps the coolant was not topped up to the correct level after they bled the system. Quote Link to comment Share on other sites More sharing options...
gunny reed Posted March 14, 2016 Share Posted March 14, 2016 Faulty radiator cap it happened to me I replaced it and it's been good ever since. Quote Link to comment Share on other sites More sharing options...
Richf Posted March 14, 2016 Share Posted March 14, 2016 Can be tricky to bleed the system sometimes Quote Link to comment Share on other sites More sharing options...
Adrian@TORQEN Posted March 14, 2016 Share Posted March 14, 2016 My money is on airlock, the coolant system needs to be bled properly. 1 Quote Link to comment Share on other sites More sharing options...
Guest Posted March 14, 2016 Share Posted March 14, 2016 Thanks Guys. They said they spent 4 hours trying to bleed the system properly on Friday and charged me for 12litres of coolant so I'm hoping they bled it properly! Would an airlock cause the loss of so much coolant? There was a fair amount in the puddle in the bumper when I got to work, and a fair amount on the mrs' driveway I've just been informed... I think maybe the best bet reading all comments is to re bleed the system, flush it through, change the rad cap and re fill with coolant? I'd rather ask the garage to attempt this first than blindly start changing more parts like the water pump.. Thanks again, further input still appreciated! Quote Link to comment Share on other sites More sharing options...
Adrian@TORQEN Posted March 14, 2016 Share Posted March 14, 2016 So there's a leak in the coolant? How's the coolant level looking now? Quote Link to comment Share on other sites More sharing options...
Guest Posted March 14, 2016 Share Posted March 14, 2016 The coolant level is below minimum now. Having been at max on Friday about 30-40 miles ago. Looking under the bonnet this morning when I got to work after feeling the freezing cold vents there was a puddle inside the bumper inner and looked to be spray marks from somewhere all over the engine cover and bonnet inner, not sure where its from but the rad cap appears to be weeping... Quote Link to comment Share on other sites More sharing options...
Ricey Posted March 14, 2016 Share Posted March 14, 2016 Lolz. I think you've answered your own question bud. You've got a leak. Back to the garage. If they've pressure tested it and it's holding pressure then I'd ha e to assume the cap is the problem. Sent from my SM-G900F using Tapatalk Quote Link to comment Share on other sites More sharing options...
Ebized Posted March 14, 2016 Share Posted March 14, 2016 Can't find the Nissan procedure for refilling the 350z coolant (there does not appear to be a "How To" guide on here) but this guide supplied by Samco is quite helpful with the images - see the end part about the refilling steps: http://crackaddict.c...samco.howto.htm From previous posts over the years on here the refilling procedure, if not followed to the 'letter' has been the downfall of many and initially I was thinking of an airlock, although in your case the loss of fluid would suggest something else as others have suggested above, is amiss. And you are best off using the Nissan Premix solution, should you have to drain and refill again - see here: http://www.350z-uk.c...genuine-nissan/ Quote Link to comment Share on other sites More sharing options...
ZMANALEX Posted March 14, 2016 Share Posted March 14, 2016 Here you go: From the workshop manual for a N/A car. NOTE IT IS CRITICAL THAT THE FOLLOWING PROCEDURE BE FOLLOWED EXACTLY! IT IS TIME CONSUMING, HOWEVER, ESSENTIAL! 3.1 Remove bleader in the stock upper heater hose. 3.2 Fill radiator and coolant recovery reservoir with anti freeze coolant. It should take 10 quarts, including reservoir. It is important that the coolant is poured through the radiator filler neck at less than 1.5 quarts per minute, in order to allow air in the system to escape. 3.3 When the engine coolant overflows the at the bleader, re-install the bleader 3.4 Warm the engine to the normal operating temperature with the radiator cap installed. 3.5 Run the engine at 3,000 RPM for 10 seconds and then allow it to return to idle speed. § Repeat this action three times. 3.6 Stop engine and allow coolant temperature to drop below 120°F. Use a remote electric fan to assist in this process. If necessary, refill the radiator and reservoir up to the filler neck. 3.7 Repeat steps 3.3 to 3.6 at least two more times (it may take more) with the radiator cap installed, until the engine coolant level no longer drops. 3.8 Check the cooling system for leaks with the engine running. 3.9 Fully warm the engine and listen for the sound of coolant flow through the heater unit, inside the car; while running the engine from idle to 3,000 RPM, with the heater control set at several positions between cool and warm. Repeat this action three times 3.10 If any sound is heard, continue to bleed excess air from the cooling system, by repeating steps 3.3 to 3.6, until the coolant level no longer drops. 2 Quote Link to comment Share on other sites More sharing options...
Ebized Posted March 15, 2016 Share Posted March 15, 2016 With the post above it would be good if that procedure could be added to the 350 guides sub-forum. 1 Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.