Kazza

Hi all, I've got vibration under mid/heavy braking, most pronounced when braking going down hill. I've also got a constant "rotational" noise coming from what sounds like the front left wheel (drivers side). With the wheel jacked up, I can hear a consistent "uneven" frictional sound at the same point when I rotate the wheel or rotor by hand. So... I decided to Inspect the front brakes today for the first time since I got the car (45k km ago, 160k km on the dial now) and made a few observations. 1. Brake pads are worn down pretty low. Front (of rotor) Pads = 1/4 inch, Rear (of rotor) pads = 3/16 inch. 2. Rear of rotor pads are worn on the top and bottom edges more than the middle - see HERE. 3. Front left rear of rotor pad tapers to one end - see HERE. 4. Rear of rotors (both sides) have a smaller "clean surface area" than front. Heavy rust band on inner and outer circumference. This coincides with the rear of rotor pads being worn down on the top and bottom edges more than middle - see HERE. 5. The wheel bearing cap has taken a beating at some point (all dented round its circumference) probably from the car being driven with the wheel not on properly. Might be a non issue but its the drivers side (where i'm suspecting the noise is) - see HERE. I'm definitely going to replace the pads, but my concern is the condition of the back of the rotors and this wear pattern on the corresponding pads (observations 2 and 4) .. is this normal or are my rotors kaput? Also, for point 3 - should I be concerned with anything other than the pad/rotor for this tapered wear? Thanks in advance.. K

Update; Checked my fan clutch and it's tight enough. Only 1/4 or 1/2 spin after engine warmed up. Showed my video in OP to the mechanic and he said that's not head gasket as it would be more pronounced bubbling or fuzzing and since I've had the problem for a year it would have gotten worse by now if this was the result of a very minor failure in the gasket. On the pump he reckons this car has metal fins and so the pump would either fail or work properly, so if it was the pump id have more serious overheating due to pump failing to circulate coolant properly. He reckons not to bother with combustion test (doesnt reckon itll show up) and just live with it if I've tried all else.. easier said than done! Might just get the test done for peace of mind..

No chalk on the rad cap. No bubbling in coolant res after shut off No misfiring of engine ever since I have owned it. I'm going to check fan clutch and get a combustion gas test done. Will keep note on the pump.. also isn't there a 2nd thermostat behind the engine? Could this be causing the problem?

Forgot to mention, I replaced the rad cap with a Gates.. it looks the same and has the same PSI rating (13) as oem? I'll probably grab one of these kits as a next step.. Oil cap is clean underneath.. no residue. I feel like if the thermostat wasn't opening I'd have much bigger overheating issues? I could try running without the thermostat to see what that yields. I'll try the fan clutch tomorrow. If That's good and the compression test passes then perhaps I'm looking potentially at the pump then. Nobody touched on the video I linked too.. seems normal? Also... how does everyone else's hoses feel at running temp? Mine's are really solid.. feels like too much pressure.

Double post

Double post

Hi guys, Had a bit of a saga over the last year and a half with my pathfinder overheating and never really getting to the bottom of it. It all started when the car overheated while climbing a hill in winter in 4x4. I didn't notice the temp gauge (because the car never had issues in the past) and it did max out unfortunately before i shut her down. After this incident, I started reading online and heard that the cooling system in the VQ35DE's can be notoriously hard to bleed. I went through all the the different weird and wonderful methods of purging air but the temp gauge still started creeping up on longer, slow climbs. Also, the coolant hoses would be rock solid (overpressured?) shortly after the car reached operating temperature, and the top hose and top of the radiator would too be hot to touch. After a few months of "managing" the problem (running my heater on full heat), I looked into it again and this time decided perhaps that I had poor circulation in the cooling system either due to the thermostat not opening properly or the radiator being blocked in some way. So I went about replacing both of these and bleeding the system again but still this did not fix my problem. Again, I went back to just managing the problem until a few weeks ago I noticed I was losing coolant at a fair rate (1/2 litre per week). I took the car to the garage and they diagnosed as the coolant crossover pipe behind the engine, passenger side gasket leak. Big job, big $$$ (I was quoted almost the value of the car to change this gasket)... i reluctantly decided to throw some K-SEAL in until I figure out next steps. The K-SEAL, to be fair, has stopped the leak for now - I'm not losing a drop of coolant anymore - and I plan to flush the system soon to remove the excess K-SEAL. But I'm still left with this concerning (however manageable) overheating issue and, what feels like, an over-pressurized cooling system. Now.. something has came to my attention since adding K-SEAL and having the small metallic particles in the coolant. In the linked video below you will see that there is a constant stream of micro-bubbles or fizzing coming up to the surface of the coolant in the funnel attached to the radiator neck when the engine is running. This may just be evidence of normal operation - the coolant flowing from the pump into the top of the rad - but I have nothing to compare it to and my mind is questioning if this may be a very small but significant enough leak of air/compression/gasses from the engine (head gasket?). And, that it may be causing the loop to over-pressurize (rock solid hoses) and also causing poor coolant flow (overheating) as a result. Note: I have none of the classic failed head gasket symptons - e.g. white smoke, milky oil/oil cap, loss of coolant into the engine. Here is the link to the video; apologies if a little faint but you should be able to see the slight fizzing and displacement of metallic k-seal particles, mostly to the left of center. Also summary of problem and diagnostics thus far; - Car temp gauge rises on long, slow/low revs incline. Turning on heater and/or increasing revs brings the temp gauge back to middle. - Coolant hoses and top of radiator run very hot (too hot to touch) shortly after reaching operating temps. - Coolant hoses become rock solid at operating temp, but lose pressure again not long after engine shut down. - Replaced thermostat and radiator - No loss of coolant (crossbar coolant leak fixed for now) - No air in coolant system - Clean oil (to the eye, not tested) - Clean coolant (to the eye, not tested) Appreciate any and all input on this... its been haunting me for a while now. Cheers, K

Thanks guys - yes looks like valve cover (passenger side). I can see, looking in the engine bay, some oil wetness along the join between the valve cover and block. It looks like a lot of work to change the gasket though - the leak seems to be very minor. I'm not losing oil at a meaningful rate. @Mr_Reverse is it possible to tighten the valve cover screws without taking much of the top part of the engine off?

Hi guys - got a small oil leak of some sort looks like its coming from the back of the engine, its also looking a bit "wet" around the transmission oil pan seal. I did have the dreaded coolant crossover pipe leak which I think I have fixed (for now) with some K-Seal that I reluctantly put in as the fix looks to be either too expensive or outwith my capabilities at the moment. I'm not losing coolant anymore and not seeing any wetness arising from coolant, but the oil droplets seem to be coming from a similar area. See pics attached. Any suggestions on where to concentrate efforts?