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Discussion Starter #1
Man, I just bought the GTV6 and drove it 1,400 miles without incident (for the most part). I took it to get smogged the other day...failed the first try so the tech says to leave it idling and get it warmed up. Next thing I know, he says he's done with the test and it passed..good news. Except, its now overheating and barfing coolant from the overflow.

I take it home, next day I refill coolant and drive around. Driving around town, its driving great, no overheating. Then all of a sudden, it loses power and revs like my mom's old Chevette...no power. I coast to the side of the road.

It won't idle without some pedal and sounds like half the cylinders aren't firing.

Took it to the mechanic today and so far he stumped. Last theory was maybe a clogged catalytic. Seems to me like a fuel delivery issue, but not sure he's tested that yet.

Any ideas on what could fail while driving around like that?
Could it be related to the short-lived overheating?

I hope this isn't a sign of the ownership experience...I'm really hooked on this car already!
 

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Start with the easy stuff, check all your air hoses and eletrical connections. It sort of sounds like you may have cracked your main air hose, or a hose connection got loose and now the car is running very lean. It might be a good idea to invest a little in a fuel pressure gauge, that way you know when you have fuel pressure, spark is easy to test. It sounds like you have both, but maybe not enough fuel. One other thing to test is to see if your belt skipped a tooth or two, happens on the passenger's side. Grab the belt and see if the tension is still tight, if it seems loose, you may have skipped a tooth or two. Hopefully it is an air leak, we will pull for that one...
 

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Usually a clogged catalytic converter will prevent the engine from running at higher speeds but it'll idle OK. (the clog restricts exhaust flow to a small amount - enough to idle but more).

Just like our Spiders, L-jet is very intolerant of 'false air' - intake air or vacuum leaks so check for those very carefully. The only problem we had when we drove our new-to-us GTV6 home from Houston, TX was when the intake air duct became loose from the AFM. It was sitting close to the AFM but not securely attached. It would act like it was running out of gas or the injectors were clogged and didn't idle well. A quick look was not sufficient to see the problem until I yanked on the air duct.

The electrical grounds are also very important. Print out Greg's V6 tune up/diagnosis page for your mechanic.
 

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failed the first try so the tech says to leave it idling and get it warmed up. Next thing I know, he says he's done with the test and it passed..good news. Except, its now overheating and barfing coolant from the overflow.
Congrats on passing the emissions test. I thought everyone knew to get the engine (and cat) warmed-up before testing.

I'll just say this as it pertains to Alfa's. If you don't personally know the mechanic or shop that's been servicing an otherwise unknown-to-you vehicle, don't drive it without first going through the obvious stuff (esp. if it's been sitting for a long time). Obvious stuff being timing belt, rubber hoses and belts, charging system, fuel system, cooling system, and braking system. Safety first for you and any passengers and of course, protect your investment. You can do some serious damage to your wallet if the timing belt breaks, skips badly, or engine overheats on your maiden voyage home.

I hope this isn't a sign of the ownership experience...I'm really hooked on this car already
You're lucky she didn't leave you stranded in the middle of your 1400 mile trip. I'm a bit surprised that after an overheating event, you just chucked water in and started driving it around again. I'm afraid that your ownership experience will be filled with events like this and consequent posts on the board asking for help and damning the marque.

Investigate why she overheated and correct the deficiency. Have cooling system flushed and make sure radiator fans come on when they're supposed to.

oh, and have fun driving your new GVT6 - I drive mine all the time. Reliable, fast, and safe.
: )
 

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overheating

Your overheating issue could be why the car was up for sale. Chances are that the engine had overheated several times before causing and worsening the problem. You might consider a possible intake gasket leak and warped head/manifold creating your lean miss and stall problem. Good luck
 

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Discussion Starter #6
Sam, I'll see what the fuel pressure is like...hopefully is an air leak as you said. The timing belt was very tight, but I'm curious to know what would happen if it skips a couple of teeth...its not a violent crash like a complete failure? Mechanic is checking this possibility too.

Eric, I'll get a copy of Greg's diagrams to the mechanic. Thanks.

ToonRboy: I had the timing belt, tensioner, water pump, etc changed before the trip. It was done by a well-known Alfa shop, but there were some problems with their work, so its anyone's guess how competently they did the job (see this http://www.alfabb.com/bb/forums/alfetta-gtv6-1975-1986/175361-new-gtv6-owner-now-roadtrip.html#post964856). I did warm it up really well before bring it in or so I thought, but I guess there was an '11'. The drive around after adding coolant was to see if it would overheat again or if it was due to the smog guy having it at high RPMs with just the fans cooling it down...in any case I was scheduled to have it checked out the next day. Glad to hear your GTV6 experience is good....gives me hope.
 

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Discussion Starter #7
Your overheating issue could be why the car was up for sale. Chances are that the engine had overheated several times before causing and worsening the problem. You might consider a possible intake gasket leak and warped head/manifold creating your lean miss and stall problem. Good luck
I don't know...I was in traffic and drove all those miles and no overheating.Granted its during winterish conditions but in the southwest so it did get up around 80 at times..but no problems. I would think the problems with mixture / warpage would've been felt right from the begining? It ran beautifully until it crapped out.
 

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At idle and at rest your water pump is cycling only a fraction of coolant through the system as opposed to running down the freeway at 70 mph. Also at idle there is zero fanning effect from forward motion which causes a significant rise in engine temp. If you have ever dyno'd a car you will see a huge fan placed at the front of the car simulating a real world test drive. Some over heating problems can be masked by ambient temp and the speed of the vehicle. Its easy to assume that you could be ok on your journey home but at a stationary idle the over heating problem reared its ugly head. Get a propane torch and with the knob on but not lighted start you car and trace the intake manifold shape with the torch. If your idle goes up you know that you are pulling propane into the intake stream consequently showing you where the leak is . Hope this might help
 

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Sounds like a problem with the fan not coming on at idle when it should intermittently. My 2 GTV6's would idle all day and stay at normal temp, the fan working on and off as it should. My 91S had a problem with the fan speed resistor connections being burnt, not conducting occasionally, causing overheating. Had to make new connections. Don't remember if the GTV6 has the resistor.

Also sounds like the ignition system, ie, plugs, cap and rotor might need a new look at, dirty worn plugs easily causing the engine to not idle, some cylinders not firing. My 91S just went through this. Clean and gap the plugs (or replace them), clean the insides of the cap with spray electrical cleaner and scraping off the sparking deposits on the electrodes and rotor tip.

Depending on where all the antifreeze splashed, as mentioned before, check the cam timing for tooth jump. If you don't have the shield on the distributor, antifreeze could have gotten in there as well, causing conductive deposits with carbon dust tracks inside the cap. Get the shield if you don't have it.

Also, you may eventually have to check for leaking head gaskets now that it has overheated. Try retorquing the heads first if it hasn't been done. This is a common Alfa v-6 problem, nobody retorquing heads on high mileage cars, esp the 164 with the more difficult rear head, but can solve some problems. Esp if mousse shows up.

BTW, my GTV6's were a blast to drive, esp the 86 (shouldn't have sold it, alas), and were reliable once the service (not) done by the PO's was brought up to snuff. Have fun.
 

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Discussion Starter #10
Thanks Jerry and Del. I don't think any coolant splashed anywhere...it just drained off the hose and to the ground

During the smog check, the car was put on the dyno backwards due to the lack of room in the shop. The big fan was actually pointed so it blew the exhaust from the back to the front, so there was no fan blowing at the front of the car.

The radiator fans seem to work fine and come on when they should. Idling for a long time after this incident didn't result in overheating, so maybe it was the high RPM with no external air flow (and maybe a radiator that needs cleaning out).

The mechanic said the timing belt didn't skip since the timing marks show up as OK and no problem with head gaskets. He did see extremely hot exhaust headers (600 deg) and noticed much smoother idle when he removed a small access hole just in front of the cat. So, he's thinking the cat may be clogged causing too much back pressure and possibly even some over heating. I'll know more on Monday when he removes the cat and resumes testing.

The thing that baffles me is the suddenness that this occurred, but I guess stuff happens when it happens.
 

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Fellas, don't complicate matters. His car is running fine, drove it a long ways and only overheated while idling for an extended period. If it had air leaks, or timing belt slip, it would run like crap at idle and probably wouldn't have passed emissions. Three possible culprits. Fan relay or coolant temp sensor inop, clogged original radiator, wrong coolant mix.

Long shot is a possible bad water pump, I'm not sure but I think early one's had plastice vane, newer cast aluminum. My experience has been if the pump goes, it's usually the seals/bearing and you get coolant spewing out the bottom. So, you will definitely know if the water pump goes.

My car is rigged so that both fans come on. In stock form, the 2nd fan comes on when A/C is on.
 

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There is another possibility - air in the system. When flushing the 12v V6 you must open the brass bolt on the thermostat to bleed it. Otherwise you'll have air in the system and it will overheat.
 

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Isn't this the car that the ham-fisted mechanic punched a hole in the radiator? If so, I like Toon Guy's air in the system idea. I doubt he bled the system when he replaced the coolant.
 

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Discussion Starter #14 (Edited)
The air in the coolant theory sounds plausible considering the slap-dash way it was all put together. On my car both fans come on at the same time. And the water is brand new too...preventive maintenance (or so I attempted).

I do have an update on the rough-running problem...mechanic says the timing is VERY retarded. He said it ran much better when he rotated the dizzy 1/4 turn. But he said the cap and rotor felt solid and probably didn't move. So this might have been due to the timing belt jumping some teeth. I find it a bit scary that he was running it with the timing belt off alignment...maybe I misunderstood?

He thinks it might have jumped on the aux pulley side rather than the drivers side because the driver's side was pretty taut.

Anyways, I'm going to have him recheck the timing belt and set it back if needed. The previous honest, yet grossly incompetent mechanic just put the mechanical tensioner on...I wonder if he jacked that up? Hopefully, I'll have the car back soon, but I sure hope we find the root cause so I don't have to wonder if I"m driving a time-bomb.
 

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When the belt slips, it is on the passanger's side, because of the oil pump/dizzy pulley, not much contact on that side. If the mechanic has never put on an Alfa V6 mechanical tensioner, I would print out the Alfa service instruction and get him to read it, and give the tensioner a good look over, if you use too much torque (over 17 ft/lbs if my memory is any good) you damage the tensioner, then there are arrows to line up on the tensioner on a cold engine to make sure the tension is right. It is not particularly hard to do, but best if done right.

If it overheated on the emissions dyno, I would suspect the fan switch or maybe just one fan is coming on, or a relay. Make sure both fans come on, one fan won't cool the engine when sitting still, ask me how I know...
 

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Sounds like you have two problems. Cooling and a jumped belt. Jumped belt almost certainly means improperly installed de-tensioner.
 

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Discussion Starter #17
Yep, two problems. Current mechanic has been fixing Fiats and Alfas for a while and his GTV6 manual seems pretty frayed, so hopefully thats a good sign :)
 

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Yeah, that happened to me once. Had just got Milano Gold back from shop to replace a leaking cam hub seal. The mechanic tasked was a youngster I had never seen before. A week later it jumped when I let out the clutch after letting off the accel while on the uptick. Jumped a tooth and ran like crapola. That car had the mechanical type de-tensioner.
 

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Discussion Starter #19
Sounds just like what happened to me. Was accelerating from a stoplight, shifting from 1st to 2nd and then lost power...not doing anything crazy at all. I'm just glad this happened 2 miles from my house and 3 miles from the Alfa mechanic and not on the outskirts of El Paso.
 

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And the verdict is...? For sure the belt skipped...? Let us know please!

Also, just to cover an additional base; check for milky white crud under the oil-cap, check the dipstick and check the coolant tank for little oil clusters floating around in there! Just make sure that it did not blow a head-gasket when it overheated!

Also, run it warm at the end of the evening, park it outside and come back early-early in the morning WITHOUT starting her up; pull all 6 plugs and look carefully at each sparkplug tip - look for moisture / condensation droplets around the tip of the plugs... Just to be sure that things are copasetic in the head-gasket / cylinder seal / liner seal departments.
 
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