blown head gasket or other?

[TX82FIAT]

Folks, had a tough night last night. Took the car out for a spin. I have been having a rattle when accelerating under load. Car was fine as long as i did not put my foot in it. I have also been noticing a small amount of blue smoke when accelerating. I attributed this to a possible ring or valve issue putting a little oil in the cylinder but did not think it was too serious and was only burning about a Quart of oil every 300 miles or so.

Well, I had do accllerate hard to from a dead stop to enter the highway from a small access road on a busy raod. By accellerate hard i mean up to 4500-4700 RPMs in the first few gears. Not really pushing it to hard. As I shifted into fourth I hear a pop and thought wow... that was a backfire. Pull up to the light and the car starts to idle real low in the 300-400 range and stalls. She normally idles at 1000-1100 when running for more than 20 minutes. I'm at a busy intersection so I work to get her started. She will not start unless I give her a good amount of gas. I'm able to pull out of the intersectiopn and immediatley notice the temp needle jumping up faster than I have ever seen a car heat up. Within 30 seconds to a minute the car is at 260 and i am looking for a spot on the side of the road to park and let cool down. I pop the hood and can hear coolant gurgling through the car. The overflow bottle is rising quick with the tell tail gurgle bubles. It does not overflow. Wait an hour and see if i can limp her home without overheating. She starts with a lot of gas again but is clearly missing and running very rough. I pull her over and call the tow truck. No sign of external leaks oil or coolant escaping from the head or anyplace else in the system.

blown head gasket? Thoughts. I've never blown a head gasket before so I'm not sure but would think this is what a car would do if it had a significant coolant issue inside the engine. I'm at work this morning and did not have4 a chance to check the oil or coolant for cross contamination yet.

[grittracing]

The blue smoke is normaly fuel related oil is black smoke ,but everything else kind of sounds like when my head gasget last year. also check your oil does it look milky or with bubbles if not check or radiator over flow to see if it has oil in it if either of these than it is the gasget

[maytag]

The blue smoke is normaly fuel related oil is black smoke ,but everything else kind of sounds like when my head gasget last year. also check your oil does it look milky or with bubbles if not check or radiator over flow to see if it has oil in it if either of these than it is the gasget

In my experience, that's opposite. Blue smoke is oil. Black is fuel. and unique smells associated with both.

you've already suggested the first thing I'd check: cross-contamination.
when it's cold, remove the radiator cap, then start the motor. Watch for bubbles in the radiator.
You can also learn alot by pulling a plug and inspecting it. And as long as you're at it, a comp test will be very, very useful in identifying or eliminating some things.
I've never "heard" a head gasket "pop". I imagine it's possible. Usually, for me, the symptoms show-up unannounced.

[grittracing]

maytag you are probably correct on the smoke think i did cross them up

[TX82FIAT]

The more I think of it the pop may not have been the head gasket itself but the engine backfiring because of the air/fuel/oil mix with mutliple detonations. No sign of a craked block but I'll know that later.

[maytag]

let us know what you find!

[baltobernie]

A blown head gasket will usually result in a cloud of white smoke out the exhaust. Pull all four spark plugs and let us know how they look.

[Kent124]

A blown head gasket will usually result in a cloud of white smoke out the exhaust. Pull all four spark plugs and let us know how they look.

What would should they look like with a blown gasket?

[maytag]

A blown head gasket will usually result in a cloud of white smoke out the exhaust. Pull all four spark plugs and let us know how they look.

What would should they look like with a blown gasket?

most typically very white / grey. like "steamed". Because nearly ALL blown head gaskets result in coolant leaking (or rather, being pressurized INTO) the cylinder.

But one of the things you look for, especially when pulling ALL the plugs, as bernie suggested, is how they compare to each other. If you have one that looks quite different from the others, then you know there's SOMETHING going on there.

If you follow here:
http://www.aa1car.com/library/sprkplg2.htm about half=way down the page is a chart that can help you "read" the spark plugs.

[TX82FIAT]

I've got a couple things going on this weekend. I'll see what I can learn/share so others can learn from this misfortune.

[manoa matt]

Typically there are two types of head gasket failures.

One type of failure involves the gasket area between adjacent oil and coolant holes. When the gasket failes in this manner oil and water can mix. This does not typically affect the performance/power of the car, but a huge cloud of white smoke may follow you and your oil looks like chocolate milk.

Another type of failure involves the gasket area between adjacent cylinders called the fire ring. If the gasket fails in this manner you will suffer reduced power as the car is only firing on 3 cylinders, and sounds like an old tractor.

A thrid and less common type of failure occurs between a coolant galley and a cylinder. In this instance coolant can leak into the cylinder/combustion chamber. This type of failure can kill an engine quickly as the coolant cannot compress and you will bend a connecting rod.


From your description it sounds like you blew the fire ring between adjacent cylinders. On a Fiat it usually occurs between #3 and #4. The easiest way to check is to take the plugs out, turn the engine over by hand until the timing marks are lined up. At this stage the #4 piston will be at TDC and the valves closed. With an air compressor (set on a very low psi around 10 or less) or length of hose, blow air into the #4 spark plug hole. Listen near the #3 hole for the sound of air leaking.

Now remove the valve covers and turn the engine over so the #2 and #3 pistons are at TDC and #3 vlaves are closed. The reason to remove the valve covers is so you can see when the valves are open and closed. Repeat the test with the #3 cylinder and listen to the #4 spark plug hole.

If you have an air fitting with a rubber tip, that works bes as it will seal around the spark plug hole. Again, don't set the air pressure to high as you can start the engine rotating.

[TX82FIAT]

Update, I looked over the car and plugs and thought the #4 plug was in very bad shape oily/messy. The other plugs looked Ok to me but I'm not real experienced in what the plugs should look like other than not oily and not all carbed up. Looking over the outside of the engine from various angles I saw not sign of a cracked block, external coolant leak or external oil leaks. So, I rolled the car up on a flatbed and drove it up to VICKS in Fort Worth. Andy confirmed for me today that the problem was with #4. Spark plugs looked good in 1, 2, and 3. #4 was coated in oil and gooey stuff. He will be pulling the head off in the next day or so to see what type of damage, if any, we are talking about. While I could replace the gasket, I don't have a lot of confidence in my ability to determine why the gasket blew. More importantly, Once I had the head off, would I be able to spot a crack or scarring on a cylinder wall, a valve or bearing issue? I hate to admit it but sometimes it is much better to turn over a significant internal combustion issue to a professional and have it fixed right. The folks at Vicks know this engine inside and out. I'm confident they will square it all away in no time.

[RRoller123]

How regularly should we retorque the heads on these engines? I have no idea if it was ever done on mine, bought it with 68K miles. I used to have my X1/9 mechanic do it every year or so back in the day on my '79, but the car was new and was used regularly, like 30K per year. I will only run this car maybe 3,000 a year tops.

Pete

[TX82FIAT]

From what i have read the head should be retorqued about 500 miles or so after a new gasket is put on the car. I think I read someplace where Guy croft talks about bolt stretch. While I've not see it... i have read it.

[RRoller123]

Interesting. I remember my mechanic back in the day (Mario in Framingham MA, great guy, loved these cars, wonder where he is now?, former FIAT factory trained mechanic) sort of telling me I was wasting money having him do the retorque every year. Then one year he said he found a couple of the bolts under spec. I may do it on this car since I don't know the history, and be done with it. Can't hurt I suppose.

Pete