92 Q Overheated. Bubbles in reservoir tank and underneath plenum.

[SurfinGator]

Yep, stupid is as stupid does. I overheated on the freeway this weekend, bone dry. I had taken it in for a checkup at the dealer and an oil change the week before leaving. So I didn't do my usual "pre-flight" check .... pressures fluids hoses .... so I'm toast.

When I noticed the lack on power on cruise, I had the stereo on boom, it was already pegged to the top of the gauge. I jumped off the road and switched it off. Fortunately, I was 25 miles from my Mom's house in Pensacola ... and I am a AAA Plus member .... so zero cash to get her home.

Next day I filled her with coolant and she purrs like a kitten. But she heated up after 10 miles or so down the road. I pulled the tstat, but she still heats up after a few miles. I found a small leak at the inlet line to the reservoir, probably where my coolant went over time. Once she heats up I get a bunch of bubbles in the reservoir tank. I also have a small puddle of coolant underneath the plenum which bubbles .... and no leaks I can see from any hoses.

So some questions ..... at 130K miles do I just walk away? .... spend the money for a head gasket/new hoses replacement there? ... or flush and drop a bottle of Bar's Sealent in the radiator to get her back here to replace them myself?

any input would be greatly appreciated ....

[SurfinGator]

Oh yeah ... no smoke out the exhaust and the oil is clean... just cooked.

[maxnix]

Want to do a head gasket job and check the heads for warpage?

Probably did a lot of damage, but if no water in oil and compression still good, get a thermostat and report back.

[DAEDALUS]

So sad to see a Q go like that. Once a Q overheats, there's at least a fair chance it'll need much more than a head gasket to get it going again. If you check the codes (do it--I'm curious) and the knock sensors come up, that's $400 right there. Add $500 for all the hoses. $300-500 for head work. $400 for a gasket set. Labor cost to R&R everything unless you do it yourself.I'd probably see if I could fix the leak, and run a combustion gas test on the coolant to confirm the HG (long shot). If the results aren't good I think I'd recommend either swapping the engine with a known good one or parting her out. It's what I recommend, but probably not what I'd do.

[SurfinGator]

what makes it tough is I have a remanfactured trans the dealer put in 15k miles ago .... and the interior is the cleanest of any 92 Q. But haven't done the chain guides yet ... or anything other than the MAF and fuel pump.

And I can't do the work at my mom's .... no garage and the homeowners there would fry me for even changing the oil in the driveway... so I would have to put it in a shop .... $$$$.

Can anyone guess a dollar amount a reputable shop would charge to do the heads? If it is warped I would replace it with a good used one from one of our members, would be the best option I think.

Anyone have any luck with coolant sealent like Bar's or AlumaShield? It would really be nice to get it the 245 miles to Jackson.

[DAEDALUS]

I think the worst they could do is clog the radiator. Not a huge risk at this point, all things considered. Are you 100% certain the coolant on the engine is coming from the HG? There are a couple hoses down in the back of the valley. Also check the ones that go to and from the TB.A former member had a head reworked due to chain guides and it cost around $2300 several years ago as I recall, including all parts and labor.

[Jesda]

The Bar's Leak powder tube worked to seal up a leak I had somewhere. Do not, I repeat DO NOT USE the "LIQUID ALUMINUM", which ruined my radiator. Dont use the bottle of pellets either. Also note that it can take quite a bit of driving for the powder to take effect. Start by using half a tube of powder.

I suggest fixing the leak instead of using the sealant.

[SurfinGator]

Did that $2,300 include having the guides replaced? I would pay 2.3 to have new hoses, knocks, guides, and the heads worked.

other than suspension, I would then have a new $54,000 car .....

[SurfinGator]

How long did the fix last J? I would be driving 245 miles through miles and miles of back water towns to get it here.

and if it is $2300 to just fix the leak .... anyone looking for a transmission or a slightly used MAF?

[DAEDALUS]

The $2300 was to pull 1 head and replace 4 valves. Nothing else, except for whatever got destroyed in the process, like hoses. I know the guides were original, 'cause I replaced them later. I doubt knock sensors got replaced.

[Q45tech]

Head gaskets rarely fail on all aluminum engines V8.........they fail on mixed iron/aluminum engines from dissimilar expansion rates.......or stupid supercharging

Of course if you allow the engine to get so hot that the oil cokes and still allow it to run ------all bets are off.............best to just replace the engine. Simpler and frequently less expensive to get it right for the next 100,000 miles.

All engines SHOULD HAVE a cylinder head temperature gauge not affected by coolant level or steam!!!!!!!!!!!!!!!!!!!

IT WILL SAVE YOU $5000! In fact an auto shut off with a VOICE warning/loud beeper count down -------------should be mandantory.

[Q45tech]

A transmission attached to an overheated engine is probably HURT due to conduction of block heat to transmission case and lack of ATF cooling via radiator heat exchanger...........another reason to have an external add on air to ATF cooler.

For sure it won't be the same afterwards depending on ambient and miles driven during the overheat. Immediately do a chemical flush and ATF change.

[Th4rg0r]

Ok, for future references ... I'm really curious now ...

How long theoretically (with no overheating), can a regular head gasket last? Saw from the manual that it has a larger width than regular gaskets, but never saw one up close before.

1) More importantly, what are the things to watch out for to see if the head gaskets are in order? Any important symptoms of indication or does the engine just blow when it gives up ?

2) Is there any way to check/test if it's going?

3) Will things like leaky coolant, leaky valve covers, causes a premature failure? How about old tubes?

Really curious, and hope someone can enlighten me.

Cheers to Q's,and to all her lovers, heehee

Shang

PS: ****, cannot get that Q with white leather off my mine.

[Jesda]

How long theoretically (with no overheating), can a regular head gasket last?

Forever, really.

[97Q45t]

SurfinGator,My car (1997 Q45) had the exact same problem. If your oil was fine, then I'd say 99% is your car has a clogged radiator. Note that my radiator was new too (less than 15K miles on it). Check the coolant reservoir to see if there's any kind of flake on the inner wall. Here's the link on the discussion of my overheated engine:

zerothread?id=119387

[SurfinGator]

Yeah, I intended to do a replace of ATF .... but the chem flush sounds wise. I dropped it right off the road once I saw the gauge .... so really no more than a few miles running hot imo.

Also, my problem could be a clogged radiator .... but the fluid underneath the plenum would signify something is leaking there too.

The kicker .... she runs just as quick as before and the idle is fine. No water vapor in the exhaust or in the oil. The oil was smoked, but not coked .... I have seen coked oil and it is pitch black.

The more I have picked up on this problem, I think the heads and valves are fine. I am looking for a nissan shop in Pensacola ... will holler back once I get a full diagnostic ran.

thanks guys!

[Q45tech]

Under plenum coolant [and fuel line] hoses leaking is a common maintenance item usually every 70-120k or 6-7 years depending on local ambient and annual mileage ...........even with the best of coolant maintenance!

Just a fact of life like KS failure or dirty plenum.

When ever you pull plenum to change the 15 other hoses, change the KS to avoid duplicative labor soon.

[PalmerWMD]

IT WILL SAVE YOU $5000! In fact an auto shut off with a VOICE warning/loud beeper count down -------------should be mandantory.

I like this idea best:

"Warning! Engine Overheat in progress. Engine shut-off in 10....9 ...."

Fred..

[Q45tech]

I had an 85 300zx that talked to me.......fuel level, seat belts, lights --guess I missed those conversations always thought the Q should have continued in this manner..........." Stupid Jin you put regular fuel in me" " you have not changed my oil in 90 days Cheap Skate" ABUSIVE messages for abusive owners.

Instead of a fuel pump buzz...........a continuous whinning voical reminder every time the engine rpm dropped to idle.

"We have the technology, we can rebuild him" and the Q could send you wireless email reminders all night long when parked near your home. It could call you at 3AM to remind you.

Better yet it could order new parts and set up appointments for service. Force you to work overtime to pay for its PROPER SERVICE. HARASH you continuously just like a wife or girlfriend/mother, etc.

I love the idea of an RFID inplant in car and OWNER.

[szh]

I had an 85 300zx that talked to me.......

Hey, me too! I became known among the younger ones in my family as "the uncle with talking car"!

Z

[szh]

"We have the technology, we can rebuild him" and the Q could send you wireless email reminders all night long when parked near your home. It could call you at 3AM to remind you.

Better yet it could order new parts and set up appointments for service. Force you to work overtime to pay for its PROPER SERVICE. HARASH you continuously just like a wife or girlfriend/mother, etc.

This in in the works! My company is working with a certain car manufacturer (has to remain nameless for now) for making such a product and it is wireless using our network.

The car's CAN bus will be connected to an intelligent module that will send a transmission (during the warranty period, and with the customers permission) to the service guys to report on problems (like from the on-board oil analyzer, ECU, TCU, etc.) Then, they can call you to make sure that you bring the car in!

Model year 2008 is when this is likely to be deployed.

Z

[Jesda]

Cadillacs have a system where, in the event of overheating, the vehicle goes into limp mode and operates on four cylinders with limited speed. You also get a big warning message on the dash.