does my mechanic know what he is doing?

[longrunQ]

I took my 1991 q45 to the shop today to get some things done.

I wanted a radiator flush, and he told me that their policy is to replace with coolant only. I read somewhere where palmerwmd said that a 70% water 30% coolant was optimum. Is there a risk of ruining something if they use only coolant?

I also flushed the differential and replaced with synthetic 75w-90 . It was a horror to put in and he kept getting frustrated. He used around two quarts. I am afraid that he might have used less because of the hassle. How many quarts should go in the differential? We had originally ordered three quarts.

I did a transmission flush which I was quite happy about. We flushed the transmission with 20 quarts of regular ATF and by the end, it was coming out as crimson as it went in. We then let it drip drain for about two hours while we worked on the differential.The gasket we ordered was the wrong one so the car is still in the shop till tomorrow. We will be running synthetic "blend" valvoline ATF

I had the oil replaced to 10w-30 mobil one. I had been using 5w-50 for the last 3 weeks and I was not comfortable

Next, I will install the transmission cooler and replace the fan cos its cracked. Any other inexpensive things I can do? I would really like to get a 93 TCU but no one around here has it. How about sensors. Should I replace the 02 sensor and where can I get it?

[DAEDALUS]

The AF mixture can vary quite a bit depending on your climate and your vehicle. In So. Cal. it's not something I worry about too much and typically run 50/50. Water has a higher heat capacity than AF, but AF has a higher boiling point. Thus the more water, the more heat needed to raise the temp. But boiling temp will rise as AF % is increased.I have never heard of anyone (or shop) running pure AF. I thought 20 or 30% of either is the least you could use. AF induces corrosion by nature. Inhibitors are added to slow the reaction.

[Q45tech]

Since most shops use a 20 gallon diff lube container on wheels with an intergral hand pump and hose hooked to fit in differential. Bringing a few quarts is confusing if they don't have a giant hand pump or something to force it in.

There is lots of difference in generic shops and one that specializes in Q, only those that see 6-8 different ones per day say 600-750 per year can devote the time necessary for research.

We see more 90-93Q than any of the 5 dealers in Atlanta, probably more than the two newest combined.Between our two shops we install over $500,000 of Infiniti parts per year.

I doubt there is any tech [a few that worked for us and returned to dealers are the exception] in US that knows more about early Q than our T3 group so it is unfair to expect every dealers much less independents to be experts.

[DAEDALUS]

The diff takes just over 1.5 qts (3 1/8 pts). Yeah, tricky thing to do from the store bottles. Here's an idea...if you ever replace your fuel pump because it's humming, why not package the old one up with a switch and some rechargeable batteries and turn it into an oil pump for doing maintenance? You could do oil, ATF, diff, etc. I figure if the pump can stand up to the gasoline, it should be OK with oils too. I think 6-10V would be fine.

[911/Q45]

I saved a little bottle that hydraulic jack oil came in and it filled the differential without a fuss. Refilled it 4 or 5 times from a gallon jug of Swepco.

[Mayhem_J30]

i've used a device that works like a syringe. put the rubber tube in the oil bottle suck out, put tube in diff and fill. easy!

[AZhitman]

I jammed a length of clear aquarium tubing on the nipple of the Mobil 1 bottle and squeezed the bottle. Had to tuck it up near the tank to get the last drops, but worked perfect.

[VimyJ]

I jammed a length of clear aquarium tubing on the nipple of the Mobil 1 bottle and squeezed the bottle. Had to tuck it up near the tank to get the last drops, but worked perfect.

That's exactly what I did. It was a really tight fit on the J but it can be (and was) done.

[PalmerWMD]

I took my 1991 q45 to the shop today to get some things done.

1)I wanted a radiator flush, and he told me that their policy is to replace with coolant only. \2)I read somewhere where palmerwmd said that a 70% water 30% coolant was optimum. 3)Is there a risk of ruining something if they use only coolant? 4)We will be running synthetic "blend" valvoline ATF5)Next, I will install the transmission cooler and replace the fan cos its cracked.6) Any other inexpensive things I can do? I would really like to get a 93 TCU but no one around here has it.

1) They are confused! the resulting mix would have too low a heat capacity to grab all the heat off your heads.That policy is Crazy:eyecrazy.2)Absolutely! Good heat carrying capacity and still good boilover and freeze protection.I will run this mix thru the winter here.If you expect temps under -20C in your location during winter you can make it thicker, like a 50/50, but do that in winter only.You may also want to add a botle of redline wetter water to your mix, to reduce surface tension/water pump cavitation/bubble formation in pump and fins, this volume would come out of the AF volume, not the water volume. Also use only (!) distilled and or deionized water (58c a gallon at walmart).3)Absolutely! The heat capacity is too low this way; designers assume a coolant mix that has as a minimum 50% water in it.4) that seems to be a good ATF.5) Good call.6) bleed the brakes, use Valvoline SynPower brake fluid, has great wet and dry boilinjg points and is only an extra $1.50 per bottle than the cheapo stuff, Also exchange power steering fluid use MOBIL 1 ATF for this( Or if u have the Valvoline ATF left over u can use that too)

[longrunQ]

thanks palmerwmd,

I will take it to another guy and have it done. I tried to reason with my repair guy but he would not listen.

I looked for redline water wetter at autozone and oreillys but they did not have any.

I also looked for distilled water at those places and at walmart and found none. I'll get deionized as you mentioned.

I still have 5 bottles of the valvoline ATF left over. I ordered 11 quarts because the service manual said it had a capacity of 11 quarts, but the guy only used 7 quarts. Should I add more?

How do you bleed the power steering fluid?thanks

[PalmerWMD]

thanks palmerwmd,

1)I looked for redline water wetter at autozone and oreillys but they did not have any.

2)I also looked for distilled water at those places and at walmart and found none. I'll get deionized as you mentioned.

3)I still have 5 bottles of the valvoline ATF left over. I ordered 11 quarts because the service manual said it had a capacity of 11 quarts, but the guy only used 7 quarts. Should I add more?

4)How do you bleed the power steering fluid?thanks

1) pep boys carries it.2)all walmarts have it soemtimes it's just well hidden ;last time I found it in teh dringing water area of all places, next to the mineral water in same jugs (just be sure u grab one that says distilled/deionized)Also target carries deionized water (also in drinking water area)3)Check your ATF level firts before you add anything.4) Pwr Steerinbg fluid you can just exchange it with a hose.

Fred...

[Qgrappler]

Some years ago I read a Don Garlits collumn about why not to use pure antifreeze, which simply stated that antifreeze, or "coolant" while haveing a high boiling point and low freezing point, is actually, physically speaking, a POOR conductor of heat, compared to water. So if the mixture is too heavilty weighted to antifreeze, the fluid will not absorb enough heat from the block and will not give up enough to the radiator to do what it is supposed to do.

Surprised the heck out of me to find this out, but it appears to be true. Sounds like your mechanic hasnt heard.

[texasoil]

Ethylene glycol, the 99% ingredient in 'antifreeze) holds only about 60% of the heat per volume (gal, pint etc.) for a given temp rise as does water . It als has a much higher viscosity than does water.

The results are: your water pump will not move near as as many GPM of the pure antifreeze, and to remove the same heat from the engine, the engine metal will have to be 20-30 degress hotter! The combines effect can lead to engine metal softening under high load conditions. Not good for long life.

[911/Q45]

Most grocery stores have distilled water in the drinking water section. Food for Less here charges $0.69 per gallon.

[Q45tech]

If your "mechanic" allows you to call him such without making a face of giving you the finger [even behind your back], he is obviously statisfied with the title.??????

All the people I like to deal with are at minimum TECHNICANS having completed a 2 year Associates Degree [Assoc in Science] in Automotive Technology..........many are Nationally ASEE Certified MasterTechnicans which requires annual education classes and retesting every 4 years!

I would never let anyone touch a Q that didn't work for a dealer for at least 2 years and hadn't attended at least a few of the factory Q schools. We have interviewed some pretty raggy techs who had good credentials from dealerships who I would let near a Q.I know new dealers all across the US who are now searching for such people as many of the best techs changed brands when the sales dropped in the middle 90's. A day one Certified Master Q Tech can command $60-75,000 in Atlanta probably $100k in California.

I wouldn't call them Mechanics!

A good technican will have a $5,000-$10,000 Tool Box [empty cost] and somewhere between $25,000 and $45,000 in personal tools and test equipment.

Just like Toyota/Lexus a less than Master Nissan Tech can be use on the lesser models which share commonality G20/J30..ES300,GS300....the SUV [ugh].

Just like Physician Assistants are ok for many things under the direction of a Doctor...would you want one to open you up and change a part in your heart?

[longrunQ]

Ok, I'll call him a technician from now on.

My mum is a medical doctor and worked in a univeristy around professors. She used to get on me when I called a proffesor merely doctor, or when I called a doctor merely "mister". They've been through enough education to at least deserve their propers salutation.

So from no on, it Technician.

eg. My technician blew my head by running 100% antifreeze.

[Q45tech]

Demand to see credentials as certain clues may indicate an imposter........since most manuals warn against more than 60% AF in 40% water.

Those that are certified have things to hang on the wall representing money they paid to learn.

In many countries my Masters degree is enough to be called "Dokktor" or "Licendo"

[DAEDALUS]

So from no on, it Technician.

eg. My technician blew my head by running 100% antifreeze.

LOL

[firstq]

I think you are focusing on the wrong end (mechanics, ATF mix ratios, etc) - better to focus on the "doc" mom to pony up for a new Q.