New problem - 97Q Heats up while sitting

[RocKrawler]

PROBLEM SOLVED - READ BELOW

OK, new to the forum, please bear with me - I tried searching and this is definitely the hardest site to search from any I've dealt with. I have a 97 Q45 with 102K and it runs beautiful, but now when I stop at a long light or drive thru it starts heating up to the point I'll turn it off instead of seeing how high it will actually go (the line just before the "H" and the "its gonna melt line" on the other side of the "H". I can hear the fan running, and as soon as I start moving it will begin to drop at a pace matching speed. At speed it runs just below the halfway point. When it heats up it also starts missing/shaking intermittently as it approaches that danger line before the "H".

The other odd thing (maybe unrelated, I dont know) is it just lit up the 3 traction/ABS light combo on the bottom right of the cluster a few days later.

Any advice from the guru's of Q?

SOLUTION: Its also very important to check your water AT THE RADIATOR CAP AND NOT THE COOLANT RESERVOIR! Well, as much as you guys like to blame the fins being packed with debris (not saying that doesnt happen, but with 170+ cars owned it has never been the problem of overheating in any one of them) the actual problem was the radiator and the hose between the coolant reservoir and the radiator itself. The radiator had a pinhole leak that did not leave puddles where I parked it, and the hose from the reservoir had some small cracks. According to the new mechanic this caused enough vacuum leak to not pull coolant from the reservoir into the radiator to keep it full. In other words, the radiator was massively low on coolant but the plastic coolant tank reservoir was still full. They found the leaks under a pressure test and the new radiator and coolant reservoir hose has completely solved the problem, it runs cool and beautiful again. It also has me wondering why my old LS400 can have over 200K on everything original and have zero issues and a Q45 with 100K has problems. I guess that speaks to Toyota's quality.

Hope this helps someone experiencing the same problems I did - this was a frustrating set of circumstances and fortunately the problem was solved before any damage was done to the engine.
Modified by RocKrawler at 8:00 AM 9/28/2008

[maxnix]

Condition of belts and pulleys? Coolant? Water pump?

Are you certain viscous fan clutch is working?

Not good to turn the engine off ehn hot and let it heat soak.

[RocKrawler]

Condition of belts and pulleys? Coolant? Water pump?

Are you certain viscous fan clutch is working?

Not good to turn the engine off ehn hot and let it heat soak.

Coolant looks good, but even straight water wouldnt cause it to heat like that. Fan clutch? I have electric unless there's something I'm really missing... And would rather have it turn off hot that let it keep cooking all the way to meltdown, lesser of 2 evils.

[SteveTheTech]

That is definitely you will want to have looked at. It could be something as simple as a blockage in front of the radiator, to something like a leaking head gasket. You did not mention whether you have had to refill your antifreeze. All Nissan/Infiniti vehicles like a good 50/50 ethylene glycol to water mix for optimum boiling point and freeze point. When it starts to overheat is the AC running, and if so are the fans running on low during normal operation(engine temp roughly in the middle of the gauge)? I'm not trying to bust you stones but there are many things that can cause this problem I would like to help you narrow it down a bit. When this happens typically there is a lack of airflow through the radiator causing a loss of heat transfer and then the dreaded overheat, or a lack of coolant flow through the radiator. Also check and see if there is heat while you are sitting there and the temp is rising.

[maxnix]

The twin electric fans are auxiliary AC cooling fans. The main engine fan has a viscous clutch.

RTFSM.
Modified by maxnix at 6:56 AM 8/20/2008

[RocKrawler]

Called my mechanic buddy, he nailed it - when its hot the fan can be spun by hand (engine off) easily when it should be nearly locked up. I originally only saw the 2 electric fans in front & assumed (yes, I know what that means) thats all the car had, looking behind the rad I saw the other engine driven fan. He's ordering a replacement clutch tomorrow & I'll report back when its in with the results.

[Q45tech]

In order to have as brand new cooling performance, the solution is simple make everything brand new especially the radiator................12 years of exposure will coat the rad fins with oxidation and corrosion inside channels.

10% degradation in each item sums up and makes for a very hot coolant!

Even electric fans turn slower and slower and move less air with wear.

[bullittandy]

Sounds like you've got the solution.

I've got a good fan clutch if needed.

Good luck!!

[RocKrawler]

I appreciate the offer, but at $56 new with lifetime warranty I'll just grab it locally. I'll post up when its in as to whether or not it fixed the problem, but its definitely a contributor.

[bullittandy]

Check it close, I tried a local (Advance Auto Parts) and the first was incorrect and the second fit but was way too "tight" and the fan roared all the time.

Good luck!!

[RocKrawler]

Ended up ordering from Napa, picking it up after work

[maxnix]

Ended up ordering from Napa, picking it up after work

The first brick in the road to a failed Q45 is often paved with a cheap Chinese brick sold by an American National automotive chain.

[RocKrawler]

Dont hold back, tell me how you really feel...

[SteveTheTech]

The first brick in the road to a failed Q45 is often paved with a cheap Chinese brick sold by an American National automotive chain.

it's funny cause it's true

[RocKrawler]

Turns out Napa sells USA made fan clutches.. so there.

[StarPD]

Condition of belts and pulleys? Coolant? Water pump?

Are you certain viscous fan clutch is working?

Not good to turn the engine off when hot and let it heat soak.

Brian is correct. Turning an overheating engoine off is bad business.For the rest of those reading this thread, if that happens, turn off the A/C, turn the heater on with the fan and temp on maximum, and increase engine RPM to at least 1500, preferably 2,000 until you can get moving fast enough to gety good airflow through the radiator. Then diagnose, or have diagnosed, the cooling system by a competent Infiniti technician.

A few other tips:Be VERY careful of those plastic and even paper bags you see blowing around on the roadway. They can get sucked up onto the front of the A/C condenser and/or radiatior and block airflow, leading to an overheat before you notice it on your engine temp gauge. AMHIK. When you do your routine underhood inspection (you DO that, don't you?), check to make sure your condenser and radiator aren't blocked by debris. Also, periodically blow your radiator out from behind with compressed air to get the bugs and crap out of the fins. CAREFUL high-pressure washing from behind helps even more.

[maxnix]

Turns out Napa sells USA made fan clutches.. so there.

Last I checked, Infiniti is made in Japan.

Nissan does rebuild their tranmissions and alternators in the US. But only Nissan sells those.

[RocKrawler]

Last I checked, Infiniti is made in Japan.

Nissan does rebuild their tranmissions and alternators in the US. But only Nissan sells those.

My point was that the part I got was not made in China, and I stated where I was buying it from, and it wasnt Infiniti.

[RocKrawler]

Need a new mechanic buddy... changed the fan clutch & same problem. When hot the fan can be spun about 1/2 turn clockwise when standing at the front of the vehicle with a flip of the finger, is that normal of is it supposed to be rigid at higher temps ?

[NightRiderQ45]

What are the symptoms if a new fan clutch is needed? I know that I was told awhile back that if you are able to stop the fan by hand easily while the car is running, then you need a new fan clutch. What are other symptoms? I've devoted myself next month to complete atleast one major maintenance on my car each month.

1) new strut mount and new stab. link bar.2) new spark plugs (my car isn't running rough; just time to put in new OEM plugs)3)....

[ViruzOne]

Unfortunately, My Q is showing the same symptoms as yours. When i let it sit for longer than 10 minutes with the engine on and AC on in Mid-day, The needle starts moving closer and closer towards the H. I first noticed it going a rigid uphill climb a few weeks ago. It got so hot I had to spend a hot summer day in the canyons with the heater on!

[RocKrawler]

Im baffled, it doesnt matter if its hot or cold, AC on or off, uphill or down - it only heats up at a standstill. If I'm moving its fine, if its stopped Im screwed. It has to be an airflow problem, and the new fan clutch doesnt have any more resistance than the old one, might be a bad clutch despite being new.

Bullittandy - how do you know yours is good not saying it isnt - just want to know how to see if it is) and how much do you want for it? I take it its a good used OEM?

[Q45tech]

Think thru the situation slowly. At 650 rpm idle the tiny amount of fuel burned creates just 7 HP to turn accesories, add ac compressor and another 3-4 are needed so the 10-11 HP of heat is the same brand new or 10-15 years old. Putting the transmission into drive from park adds at least 2-3 more HP to overcome TC friction/slip.So an engine in drive with AC on adds 7 HP to the basic 7 HP to turn the engine..............you are doubling the heat ouput of the idling engine between the 2 cases. You can see this easily by viewing the injector open time under these 2-3 situations going from 2.1 milliseconds to 2.7 milliseconds

Yet you are not doing anything to inprove the radiator performance, so the coolant must go up.

Once the coolant exceeds the fully open temperature of thermostat 194-200F everything depends on radiator and fans since rpm doesn't change much

The condensor and radiator fins get bent, oxidized, the rubber/foam seals around both no longer work well, allowing hot output air to sneak back in front of rad and condenser creating hot air leaks.

Everything is cumlative in tiny increments just changing a fan blade or viscous drive won't bring the system back to brand new you must change radiator and rubber seals sometimes even a new condeser will be required to get to the last few degrees. Many times the auxillary electric fans have slowed from age and are 10-20% below spec.

After 10-12 years everything brand new to oem spec is required if you want brand new performance.

You must TOTALLY rebuild a car every 10-12 years especially the cooling system.

[StarPD]

Think thru the situation slowly. At 650 rpm idle the tiny amount of fuel burned creates just 7 HP to turn accesories, add ac compressor and another 3-4 are needed so the 10-11 HP of heat is the same brand new or 10-15 years old. Putting the transmission into drive from park adds at least 2-3 more HP to overcome TC friction/slip.So an engine in drive with AC on adds 7 HP to the basic 7 HP to turn the engine..............you are doubling the heat ouput of the idling engine between the 2 cases. You can see this easily by viewing the injector open time under these 2-3 situations going from 2.1 milliseconds to 2.7 milliseconds

Yet you are not doing anything to inprove the radiator performance, so the coolant must go up.

Once the coolant exceeds the fully open temperature of thermostat 194-200F everything depends on radiator and fans since rpm doesn't change much

The condensor and radiator fins get bent, oxidized, the rubber/foam seals around both no longer work well, allowing hot output air to sneak back in front of rad and condenser creating hot air leaks.

Everything is cumlative in tiny increments just changing a fan blade or viscous drive won't bring the system back to brand new you must change radiator and rubber seals sometimes even a new condeser will be required to get to the last few degrees. Many times the auxillary electric fans have slowed from age and are 10-20% below spec.

After 10-12 years everything brand new to oem spec is required if you want brand new performance.

You must TOTALLY rebuild a car every 10-12 years especially the cooling system.

I wonder how many owners ever pressure wash their radiator and condenser coils from the rear, or even just blow them clear with compressed air. I also wonder how those who don't can wonder why their cars overheat at idle in summer with A/C on.

Clue: Your radiator and A/C condenser both rely on air flow to transfer heat out of them. Coils blocked with bugs, road grit, hamburger wrappers, and assorted debris don't flow air very well.

CLEAN YOUR RADIATOR AND A/C CONDENSER! (and as Q45Tech says, make sure your rubber/foam seals around them are intact and fit snugly).

[Q45tech]

Important to understand how much the thermal conductivity of aluminum changes from new to used [10 year exposure] in a radiator when exposed to atmosphere and oxidation.

This change is over and above any air flow restrictions and blockages that occur.

http://www.knovel.com/web/port...d=754

Some theretical rad homework:http://deepblue.lib.umich.edu/...t.pdf

[RocKrawler]

PROBLEM HAS BEEN SOLVED: Its also very important to check your water AT THE RADIATOR CAP AND NOT THE COOLANT RESERVOIR! Well, as much as you guys like to blame the fins being packed with debris (not saying that doesnt happen, but with 170+ cars owned it has never been the problem of overheating in any one of them) the actual problem was the radiator and the hose between the coolant reservoir and the radiator itself. The radiator had a pinhole leak that did not leave puddles where I parked it, and the hose from the reservoir had some small cracks. According to the new mechanic this caused enough vacuum leak to not pull coolant from the reservoir into the radiator to keep it full. In other words, the radiator was massively low on coolant but the plastic coolant tank reservoir was still full. They found the leaks under a pressure test and the new radiator and coolant reservoir hose has completely solved the problem, it runs cool and beautiful again. It also has me wondering why my old LS400 can have over 200K on everything original and have zero issues and a Q45 with 100K has problems. I guess that speaks to Toyota's quality.

Hope this helps someone experiencing the same problems I did - this was a frustrating set of circumstances and fortunately the problem was solved before any damage was done to the engine.

[oldmako]

An often overlooked tidbit is the rad cap itself. If the spring gets gummed up and doesn't allow its gizmometer to achieve copious and maximal fluxuation when operating at the extremis of it's epidangle then your engine will overheat in a similar manner. I had a this issue with my truck. Everything else checked out fine and I was in a full blown alcohol and angst induced frazzle when I decided to inspect the springy-thingy. One new radcap and problemo el solvo.

[maxnix]

Pressure check should have been one of the first diagnostic steps.

[RocKrawler]

didnt have that at my disposal, previous mechanic buddy went on a hunch, which is why new mechanic buddy is getting my business for diagnostics.