As far as we know we have never had an engine WE SELECTED AND R&Red for replacement fail...........some have been in 6 years.
What exactly do you mean by "selected and R&Red"? Are you saying that in a case like mine you removed the engine and replaced parts? What kind of costs are incurred? If I came into your shop, what would you advise me to do?
From what I understand it does sound best to at least replace the engine being that I have no way short of complete tear down (or at least removing the heads) of knowing the extent of the damage.
92Q Overheated!
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maxnix
- Posts: 22627
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1995 Infiniti Q45t
2000 Infiniti Q45
No, they repair and replace various components that are likely to fail before the replacement engine is installed so the engine can be warranteed 12 months/ 12,000 miles.
Youor second statement (paragraph) is correct.
Have you checked with http://www.jerrytucker.net ? He is much closer to you.
Youor second statement (paragraph) is correct.
Have you checked with http://www.jerrytucker.net ? He is much closer to you.
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Q45tech
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- Car: 1990 Q45 342,400 miles 22 years ownership with original engine
1995 G20t 5 speed 334,000 miles 16" 2002 wheels - 205/50/16 Sr20ve vvl
About a year ago we purchased a 160k Q that had a seized engine for $850. Finally got around to removing the engine as we has striped everything else.
Upon disassembly yesterday we found that 3 of the cylinders had piles of carbon and carbon was holding one valve open thus no compression...........we fully expect that this engine will return to life..............it came from an Well Known Expert BMW, MB, Porsche Aftermarket Shop where they diagnosed it as terminal [no compression and severe leak down] [signs of a bent valve?] and sat 6 month waiting for the owner to find a buyer.
Had they poured 15cc of Quick Clean into each cylinder and let it soak, the owner would probably still be driving the car today.
If German specialist can be fooled what chance has the average local mechanic. These guys deal with 32v V8, chains, and racing Porsche everyday.
Heck we missed it too, because we assummed they were correct and just started removing good parts.
There is a moral here.
Upon disassembly yesterday we found that 3 of the cylinders had piles of carbon and carbon was holding one valve open thus no compression...........we fully expect that this engine will return to life..............it came from an Well Known Expert BMW, MB, Porsche Aftermarket Shop where they diagnosed it as terminal [no compression and severe leak down] [signs of a bent valve?] and sat 6 month waiting for the owner to find a buyer.
Had they poured 15cc of Quick Clean into each cylinder and let it soak, the owner would probably still be driving the car today.
If German specialist can be fooled what chance has the average local mechanic. These guys deal with 32v V8, chains, and racing Porsche everyday.
Heck we missed it too, because we assummed they were correct and just started removing good parts.
There is a moral here.
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Q45tech
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- Car: 1990 Q45 342,400 miles 22 years ownership with original engine
1995 G20t 5 speed 334,000 miles 16" 2002 wheels - 205/50/16 Sr20ve vvl
There really is no way for ecu to know when coolant is above 235F or so since the sensor won't read STEAM!
Once the coolant gets to 194.9 F, the ecu starts removing advance 1 degree per 5F............215F is it, as far as protection is concerned. The knock sensors are rated to operate to 302F and begin to melt shortly there after.
Aluminum alloy begins to change its physical properties at 380-400F........by 500F it is significantly and permanently changed forever.
When the expansion friction increases so much that the ecu cannot maintain idle the engine shuts off, locks up, and freezes.
Then the problem gets worse when the oil if it hasn't already turned to carbon stops circulating and there is no more cooling air flow..........5-10 minutes after shut down with hood closed is probably the worst temperature.
We have seen Q drive in with 550F head temperatures all you can do is hope and use a light spray of the hose to slowly drop the temperature, use a glove to open the rad and try to add water CAREFULLY..............usually the rad is cracked and the hoses melted, water pump bearings shot, that's $1500 alone.
Then comes the real expense.
We had a customer refuse to change a leaking water pump got 15 miles and pumped out all the coolant drove back 15 miles when he noticed the overheat........by then the engine was trash!
Not uncommon when people don't understand all aluminum engines.
Once the coolant gets to 194.9 F, the ecu starts removing advance 1 degree per 5F............215F is it, as far as protection is concerned. The knock sensors are rated to operate to 302F and begin to melt shortly there after.
Aluminum alloy begins to change its physical properties at 380-400F........by 500F it is significantly and permanently changed forever.
When the expansion friction increases so much that the ecu cannot maintain idle the engine shuts off, locks up, and freezes.
Then the problem gets worse when the oil if it hasn't already turned to carbon stops circulating and there is no more cooling air flow..........5-10 minutes after shut down with hood closed is probably the worst temperature.
We have seen Q drive in with 550F head temperatures all you can do is hope and use a light spray of the hose to slowly drop the temperature, use a glove to open the rad and try to add water CAREFULLY..............usually the rad is cracked and the hoses melted, water pump bearings shot, that's $1500 alone.
Then comes the real expense.
We had a customer refuse to change a leaking water pump got 15 miles and pumped out all the coolant drove back 15 miles when he noticed the overheat........by then the engine was trash!
Not uncommon when people don't understand all aluminum engines.
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HeavyDuty
- Posts: 1281
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- Car: 1995 Infiniti Q45
95 Nissan 240SX S14
96 Nissan D21
06 Nissan 350Z Z33
If the head gasket was compromised & coolant started leaking into the cylinders, that could make it shut off, too. Water doesn't burn, it fouls the plugs.
Like I mentioned before, it wouldn't hurt to pull the heads & have them checked out by a machine shop. That would probably tell you a lot, depending on the condition of the engine before the overheating event.
If the heads aren't warped excessively, or cracked, she may have caught it in time. If they are, cracked, by all means, don't bother.
:2cents
Like I mentioned before, it wouldn't hurt to pull the heads & have them checked out by a machine shop. That would probably tell you a lot, depending on the condition of the engine before the overheating event.
If the heads aren't warped excessively, or cracked, she may have caught it in time. If they are, cracked, by all means, don't bother.
:2cents
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Q45tech
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- Car: 1990 Q45 342,400 miles 22 years ownership with original engine
1995 G20t 5 speed 334,000 miles 16" 2002 wheels - 205/50/16 Sr20ve vvl
Never seen a head gasket fail in this manner [we have looked at dozens of engines over the years] but by then [overheat] there is no water in the coolant passages, it has long since turned to steam.
The piston rings melt and seize just a few moments after the bearings.........usually the cam towers warp seizing the cams.
An over heat is a nasty thing on a $12,000 engine.
Always caused by lack of maintenance.....hoses, coolant not replacing rads, water pumps at reasonable intervals.
If you check [like weekly] coolant level in rad and overflow tank you never get surprised.
I really have little sympathy for owners who let things fail, lack of education costs money.
The piston rings melt and seize just a few moments after the bearings.........usually the cam towers warp seizing the cams.
An over heat is a nasty thing on a $12,000 engine.
Always caused by lack of maintenance.....hoses, coolant not replacing rads, water pumps at reasonable intervals.
If you check [like weekly] coolant level in rad and overflow tank you never get surprised.
I really have little sympathy for owners who let things fail, lack of education costs money.
Always caused by lack of maintenance.....hoses, coolant not replacing rads, water pumps at reasonable intervals. I really have little sympathy for owners who let things fail, lack of education costs money.
Q45 tech - I hang my head in shame! Yes, I've negelected maitainance of things such as hoses, belts and checking the water pump. I did change oil regularly as well as doing trans service/fluids. Time, money, lack of garage, long hours at work, family/in-laws obligations and 3yr old + wife conspire against me!
Q45 tech - I hang my head in shame! Yes, I've negelected maitainance of things such as hoses, belts and checking the water pump. I did change oil regularly as well as doing trans service/fluids. Time, money, lack of garage, long hours at work, family/in-laws obligations and 3yr old + wife conspire against me!
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Q45tech
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- Car: 1990 Q45 342,400 miles 22 years ownership with original engine
1995 G20t 5 speed 334,000 miles 16" 2002 wheels - 205/50/16 Sr20ve vvl
Should of said a little sympathy..............but absolutely none for people who are warned of a visible problem and decline a repair.
Like the leaking water pump or swollen under plenum hoses...... you should see the jury rigged repairs [hoses made to work, duct tape, garden hoses spliced, weird belts and rad caps.
Let them die an honorable death, so their parts can save some one else.........organ donors.
Like the leaking water pump or swollen under plenum hoses...... you should see the jury rigged repairs [hoses made to work, duct tape, garden hoses spliced, weird belts and rad caps.
Let them die an honorable death, so their parts can save some one else.........organ donors.
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Q45tech
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- Car: 1990 Q45 342,400 miles 22 years ownership with original engine
1995 G20t 5 speed 334,000 miles 16" 2002 wheels - 205/50/16 Sr20ve vvl
I was giving YOU some sympathy. Hopefully you apportion blame in your household. Send her to votech school to study automotive technology.........the tuition might [probably will] be returned in lower cost of ownership over her driving life.
As we are a long way from doing away with cooling systems for some time.
As we are a long way from doing away with cooling systems for some time.
LOL!
Back when I had a Miata and I was looking for and exhaust system as well as chassis reinforcement, I overheard her telling one of her girlfriends that "my husband is obsessed with trying to buy pipes for his car"
I've not much hope for my wife when it comes to automotive education, though I believe now, she is really open to the idea of at least monitoring her temp gauge whilst driving. I'm investing my automtive educational work on my 3yr old daughter instead (she's much more interested/receptive!).
Anyhow I'm trying to work it out with Daedalus to check out my car this weekend.
Back when I had a Miata and I was looking for and exhaust system as well as chassis reinforcement, I overheard her telling one of her girlfriends that "my husband is obsessed with trying to buy pipes for his car"
I've not much hope for my wife when it comes to automotive education, though I believe now, she is really open to the idea of at least monitoring her temp gauge whilst driving. I'm investing my automtive educational work on my 3yr old daughter instead (she's much more interested/receptive!).
Anyhow I'm trying to work it out with Daedalus to check out my car this weekend.
Well Daedalus took a look today.
The car does fire up.
Did not smoke as per the claim of the garage when the car was first brought in (unfortunately neither my wife or I was present when the car was transported to the shop). I know this shop to be reputable as they've worked on our "lesser" cars for years doing minor servicing.
There is a slightly rough idle that was not present before. But maybe the motor mounts were damaged in the overheat and might be amplifying a slight roughness that might not have been as noticable before the overheating event?
There is a coolant leak.
I've decided to patch the coolant leaks and see what happens.
Last but not least I owe a BIG THANKS to Daedalus for coming buy to check it out!
The car does fire up.
Did not smoke as per the claim of the garage when the car was first brought in (unfortunately neither my wife or I was present when the car was transported to the shop). I know this shop to be reputable as they've worked on our "lesser" cars for years doing minor servicing.
There is a slightly rough idle that was not present before. But maybe the motor mounts were damaged in the overheat and might be amplifying a slight roughness that might not have been as noticable before the overheating event?
There is a coolant leak.
I've decided to patch the coolant leaks and see what happens.
Last but not least I owe a BIG THANKS to Daedalus for coming buy to check it out!
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Q45tech
- Moderator
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- Car: 1990 Q45 342,400 miles 22 years ownership with original engine
1995 G20t 5 speed 334,000 miles 16" 2002 wheels - 205/50/16 Sr20ve vvl
Have the shop test for hydrocarbons in coolant [special kit and liquid that changes color]........the combustion gases will leak into coolant before the coolant leaks into cylinder.
Also measure hot running coolant pressure [and temperature] with a special gauge.......why rads sometimes leak -- constant high pressure but not enough to open relief cap into overflow tank.........obviously a 176F coolant can't build up much pressure compared to overheat.
Drain the oil into jugs [two gallon jugs] have some analysed.
Get a power balance and Consult reading to check knock sensors.
Also measure hot running coolant pressure [and temperature] with a special gauge.......why rads sometimes leak -- constant high pressure but not enough to open relief cap into overflow tank.........obviously a 176F coolant can't build up much pressure compared to overheat.
Drain the oil into jugs [two gallon jugs] have some analysed.
Get a power balance and Consult reading to check knock sensors.
I didn't have the room or time to raise the car and remove the lower shroud, so I couldn't determine the source of the leak, but it doesn't allow running the car for more than a few minutes between top-offs. Is it really likely to find coolant in the oil via the dipstick? I didn't see any water on there. The engine runs rough, but not a complete miss. I looked in front and behind the radiator, and didn't see any obvious leaks there. I peeked at both knock sensors between the runners, and they didn't look melted from what I could see.I'm wondering if the car overheated because it was low on coolant, and then something burst as soon as the water pump shut down? Tom's wife reported a lot of steam coming from under the hood suddenly after pulling over, but none from the tailpipe. The shop that looked at it fired it up a couple hours after the overheat, and reported seeing clouds out of the tailpipe.
It will be possible to better diagnose other things once the cooling system is back online.
Tom, I haven't used them yet, but I would if needed: http://www.blackstone-labs.com/ There's an online form to fill out. They'll send you an oil (urine) sample bottle for free, and you pay when you send it back with the oil in it. If I were to buy a $30k car, this is something I would do every 10-20k from the start, just to monitor the results over time.
It will be possible to better diagnose other things once the cooling system is back online.
Tom, I haven't used them yet, but I would if needed: http://www.blackstone-labs.com/ There's an online form to fill out. They'll send you an oil (urine) sample bottle for free, and you pay when you send it back with the oil in it. If I were to buy a $30k car, this is something I would do every 10-20k from the start, just to monitor the results over time.
OK - told the garage to simply fix all coolant leaks and that I'd take the car home. When picking it up this morning it was steaming. The garage manager told me that it's the head gasket leaking coolant into the cylinders.
Anyhow, I drove it home. Drivablity seemed really good. The car felt really strong.
I am sending my oil out for analysis. But in the mean time, would it hurt my engine to drive with a leaking head gasket? Or could I just keep topping coolant and water?
Anyhow, I drove it home. Drivablity seemed really good. The car felt really strong.
I am sending my oil out for analysis. But in the mean time, would it hurt my engine to drive with a leaking head gasket? Or could I just keep topping coolant and water?
Brian, in all his double-signatured glory, is absolutely right on this. You will regret the expense of a new motor.
I ruined a Mazda 929 by driving it around after a water pump failed, which resulted in a head gasket failure, which resulted in a timing belt failure. In the end, after spending $900 in parts and labor, the motor ended up running haphazardly on five of six cylinders. Sold it (and got WAY more than it was worth).
I ruined a Mazda 929 by driving it around after a water pump failed, which resulted in a head gasket failure, which resulted in a timing belt failure. In the end, after spending $900 in parts and labor, the motor ended up running haphazardly on five of six cylinders. Sold it (and got WAY more than it was worth).
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sijoko
- Posts: 961
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- Contact:
If you need a good rebuilt engine, try ATK. Their engines come with a 3yrs/unlimited miles warranty and shipping is included in the States.
http://www.atk-engines.com/infiniti.html
I know that Stillen resells the ATK engines for the 300zx.
-sijoko
http://www.atk-engines.com/infiniti.html
I know that Stillen resells the ATK engines for the 300zx.
-sijoko
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AZhitman
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Not hard to add one... I've got an oil pressure/water temp/voltmenter trio on my workbench, and as soon as I can grab a spare ashtray lid, the trio is gonna be mounted in the 3 holes I bore in the lid.
The voltmenter will likely be discarded for another temp gauge for the transmission inlet (or a boost gauge
)
Who the hell needs an ashtray anyway?
The voltmenter will likely be discarded for another temp gauge for the transmission inlet (or a boost gauge
)Who the hell needs an ashtray anyway?