Air can be very difficult to bleed from this system. If it it properly bled out and air returns then you have a leak in your system - Something isn't sealing (water pump, Tstat, head gasket). Many people have had shops not bleed air out properly but I'm sure the dealership would do it correctly. I use a lisle spill free funnel - works very well and much faster than just using the burp valve at the rear of the engine compartment.

 

Thanks for all the advice. They didn't have time to look at it today so I will get the next verdict tomorrow. I sure hope it is not serious.

I love the car but this has me thinking about a trade. They have a nice, very low miles 2007 premium x in red....

 

I have seen this time and time again Aftermarket shops do not bleed the system correctly they don't check your fan assembly they throw parts at it and they never fix it right the first time. This is what you need to do.. go get a funnel that attaches to where the radiator cap goes pour your 50/50 mix of choice about half way turn car on with a/c off and heat on 90. Let the car start to warm up. You will see bubbles come up, hold at 2k for about 30 seconds or until the coolant level rises in funnel, turn car of and plug funnel, let sit about 30 seconds then while car is still off pull the plug you should see coolant level drop and burp itself then open the bleed screw enough to see air bubbles coming out as soon as there's No more air from bleeder close it up and repeat the steps until you have heat at idle.

If you continue to have the funnel overflow after repeated attempts to bleed and it mainly does it when you holding higher revs then maybe your head gaskets are shot.but i doubt it. I've only seen a handful of blown headgaskets due to overheating 1 time on the vq35's. Most of the time it's just air. Hope this helps

 

It does. All this advice does. Thank you.

I will see what the infiniti dealer says today and go from there. They are bleeding it and hopefully they know how to do it. But this is great info for me and I may need to try it.

 

Any news cleverclaire? lol

 

Yep. I talked to them again late yesterday. They really feel it is a thermostat issue as well and that whatever, aftermarket likely, thermostat the import shop put in is not doing the job. They want to replace it and offered me a deal: if it fixes it I pay. If it doesn't they will eat the thermostat work. Awfully nice huh?

They ran a camera down into each cylinder and found no signs of coolant leaking. So that is very good news.

The thermostat sounds promising and they seem pretty convinced. I'm not sure. It's just that the symptoms have stayed exactly the same regardless of the repairs tried so far. Including : thermostat, water pump, clean inside and out of radiator, etc....

 

Let me just preface this that I am a mechanic of 12 years, and run my own shop. What the first place did was just completely unprofessional. Now I know we only heard your side of the story, but it does not sound like any testing was done before they told you what you needed to get done. It's one of my pet peeves, and something I have to teach a lot of new guys that come through my shop not to do (test first, fix the problem, not the symptom, and retest after to verify). They were basically guessing, and having you pay for it.

Besides no heat at idle, and overheating, do you have any other symptoms? Reservoir always low, sweet smell under the hood, unusual noises, etc.

One question is immediately after getting the car back from getting bled, do you have all the symptoms you've mentioned or do they start up over time as you drive the car? If the symptom is present immediately with the cooling system (hopefully) full and air free, then I would suspect an issue with coolant flow through the engine.

It sounds to me that the reason you are overheating and getting no heat is because you are low on coolant, and most likely have a leak. The oil change shop noted that you were low on coolant before you started having the overheating issues. Properly functioning cooling systems should lose very little coolant over time. I would have the cooling system, including the radiator cap, pressure tested. If no external leaks are found, then have internal possibilities tested. Test for coolant flow (in case of possible mechanical failure of the water pump), and have a leak down test or a chemical block test done to test for a head gasket issue.

 

Hi KFT,

I really wasn't trying to complain about the local import shop as they have treated me well and done a good job in the past. However, I can certainly see how this looks like they have been throwing parts and solutions at a problem without understanding its cause. And the fact that they asked me to approve a $2700 head gasket without looking in the cylinders to see if there is a problem is pretty damning to their case. A camera dropped into each cylinder by the dealership showed nothing but combustion results - no signs of coolant or water. I'm done with this shop now.

How do you test a thermostat without taking it out and trying another? The first thing the import shop did was just put another in figuring that was the issue. The dealership, after cleaning the hideous radiator, is basically doing the same thing. They say it seems like the thermostat and they want to replace it. Their offer is to replace it and if that fixes the problem I pay $235. If it doesn't I pay nothing and they keep looking. Seems like the same approach outside of their guarantee but I don't know if there is another way.

To answer your other questions the first indication I was having a problem was last summer on 90+ days if I idled for 20 minutes or so (emails on the road) the car would overheat and start blowing warm air. If I shut it down, let it cool for 20 and then got on the highway it would stay cool no problem.

Then 4 weeks ago at Jiffy Lube they told me my coolant was "a bit low" and topped it off. 700 (highway) miles later all was good until I took a short 6 mile drive and it overheated. I don't know if the coolant was low at that point but after it overheated it sure was. The car has never been right since.

Actually it seems to run fine for 25-75 miles after I get it back from a bleed and "fix." Then it starts all over again by blowing cold air at idle followed closely by an overheat.

The import shop said they ran two pressure tests on the system and that they did not see a leak "but it could be slow." It would be hard for me to tell if a leak is the problem at this point since the whole darn engine compartment is covered with coolant and smells sweet lol.

The thermostat and water pump have both been replaced by the import shop. Now the dealer is questioning the parts they used and they think it is likely the thermostat and maybe the water pump. At least the dealership won't charge me if they are wrong!! But if they are right I will be heading back to the import shop looking for some credit.

Ultimately, after this experience I may just trade the car. I love it and have driven it for 9 years. It runs very well outside of this problem and I have taken very good care of it. But I have been without it for over a month, have put $2000 into it SO FAR and it needs new compression arms or bushings too ($350-$1100 depending on whether I go to the import shop again for bushings or the dealership who won't do anything but the full arms).

The dealer has offered me $3500 "as it sits" for it with 147,000 miles. I am looking at an 07 with 53,000 miles on their lot now.

https://g35driver.com/forums/buying-...ml#post6885772

But I really would prefer not to write a $14,000 check although I would have a car that will probably be more dependable and cost less to own over the next 5-6 years. I am waiting to see what the service department says and also thinking about floating a low offer to the sales team for a month-end deal.

 

I actually had my water pump go out a couple months ago and replaced it myself. I skipped a tooth and ended up having to do a timing chain job and replace the tensioner. I've also bled the cooling system plenty of times, so I have some experience doing this and I'm not a experienced mechanic at all.

First off I'm leery of the dealership and import shop after reading some of your posts. The water pump is driven by the chain, so if your chain is moving odds are the pump is as well. I knew mine went out because of the bearings it would sound like a banshee yelling because it was also slightly seizing. The tensioner doesn't get "stuck" you need to crank the engine by hand slightly to tighten and loosen it. This allows you to remove the water pump and the tensioner depending on which way you go. If you over crank it you can skip a tooth and mess up your timing, which is what I did on accident. Your engine also has two small black access ports covering both the water pump and tensioner, so you wouldn't need to remove the cover unless the timing was off.

You can test a thermostat by sticking it in some boiling water if it opens in hot water and then closes in cold water it's fine.

Did they do a block test on your engine? It's a cylinder that sits on your radiator with some blue fluid in it while the car runs. If that fluid turns yellow or green it means you have exhaust gases leaking into your cooling system. That usually means a head gasket.

What does your oil look like if you open the cap? Does it look like chocolate milk at all that means coolant is mixing in also.

I also think the import and dealership are kind of adding to the problem. Changing the thermostat, removing the radiator to clean it (needed), and basically opening that system up keeps introducing air into it.

Is it possible you have a blockage in your cooling system at the heater core? I would try to bypass the heater core by connecting those two hoses together or running another one temporarily. That would at least let you know if the coolant is flowing freely and cooling the engine. What about the upper and lower radiator hoses do they feel about the right temperature.

Did the import shop use OEM parts?

 

Try not to get discouraged cleverclaire. This issue that you are having can and will be fixed.

 

Update,

The dealership has been great. They have kept my 2003 since last Monday and put 100 miles on it making sure the problem has been solved. In the meantime they loaned me a new Q50. Wow. Nice ride. They van take all the time they need.

Anyway, they seem convinced that the thermostat was the problem and that the first one the import shop put in was bad. I don't know I'd they tested it but I asked them to save the part for me. I will tAke it back to the import shop and have a conversation.

It looks like an infiniti part according to the parts guys but they said it could be a copy.

I will believe it is fixed when I drive it for a few months and it doesn't overheat again.

I'll check in again if something changes or later in the week. Thanks again everyone.

 

Well, this is kind of anticlimactic but I think they fixed the car. They have driven it for over a hundred miles and it has not overheated again.

However, I will never know for sure if it is fixed. I traded it. I'm sure it would have been fine but I got a great deal on a newer used car and I feel it will be much more reliable for the next few years.

Thanks everyone for your help. Ultimately it was a second new thermostat that fixed it. Maybe the dirty radiator was causing issues that damaged the thermostat. I don't know. But after a second thermostat replacement it seemed to be fine.