Coolant around plugs

[TeeCee]

When I bought this car I knew it had cooling issues. Right off I found a leaking heater hose and replaced it.
Well I have noticed coolant collecting in the spark plug holes. The 2 rear ones are dry but the front 2 are still collecting coolant. After the engine warms it looks like the coolant is bubbling or leaking around the plugs.
This is a 82 Spider 2000
Let me know if you have a clue as to what's wrong. Thanks

[18Fiatsandcounting]

The first place that I would check is the leak tightness of the thermostat housing at the front of the cylinder head, just in front of the #1 spark plug. Those are prone to coolant leakage if the gasket between this housing and the head is bad or missing, or if the 4 bolts that secure it are loose or not tightened evenly.

Safety tip: The 4 bolts (2 short and 2 long) that secure this thermostat housing are prone to breaking in half, so be very careful when removing. About all you can do is to be very gentle with them, and perhaps try tightening them just a tad, then loosen a tad, then retighten a tad, back and forth, until they come out.

And yes, I know that the thermostat on later model year Fiats is located elsewhere in the car, but I still refer to this housing at the front of the cylinder head as the "thermostat housing" because that's where the thermostat was on early model years.

As for the bubbling of the coolant? Probably just the water part of the coolant bubbling as the cylinder head in that area can get pretty close to the boiling point of water. A less likely possibility is that your spark plugs are not fully seated, so the bubbling you see is combustion gases leaking past the plug threads.

-Bryan

[TeeCee]

Thanks Bryan. I will check that out. Is it possible for the headbolts to leak at the top of the bolts? I have no oil in the water. I'm also having a fit with the temp gauge and the two sensors. How do I determine what is bad?
The gauge does not work. I can get it to peg by touching one of the terminals on back of the gauge with test light to ground.
How do i test the sensors?
Also I've heard talk about an online resistor. I found what I believe to be the holder (a red fuse type holder)that was under the dashboard. It had a regular fuse in it. I bypassed it and no difference. Is that resistor necessary and if so can I get it?
Thanks for responding so fast!

[18Fiatsandcounting]

Lots of questions here, so let's take it one at a time:

The head bolts should not be leaking coolant or oil around them. If they are, you've got a leaking head gasket (more likely) or a crack in the block (less likely).

At least in earlier Fiats (I can't speak for an '82 model), there were two temperature sensors located in the top of the cylinder head. One sensor measured the temperature (as read by the gauge) and one was meant to either send the gauge all the way to "full tilt" or turn on an "over temperature" light. Not sure what you might have on your '82.

What I would do is pull the wires going to both temperature sensors. Your temperature gauge should read zero. Reconnect one of the wires and warm the engine up. If the gauge never moves, the wire that you reconnected is probably the "over temperature" sensor. Try the other wire. If that causes the gauge to move up in temperature reading as the engine warms up, then that sensor is your temperature reading and the other wire is the over-temperature sensor.

The temperature resistor in the circuit should not be a fuse, but an actual resistor. But again, I'm very unfamiliar with an '82 model and so maybe I have this wrong.

Hope this helps.

-Bryan

[TeeCee]

Ok, sorry for the question attack
I have read a thread or two here about the two sensors and I have identified the wires. I bought a schematic of the wiring. My issue is how do I know what component is bad, whether it be the sensors, gauge etc. I gather the resistor is a def issue. But cant you bypass it for testing or would that be too much voltage going to the gauge?

[18Fiatsandcounting]

TeeCee, at this point, I have to ask what is wrong with the temperature gauge? Does it not work at all (needle doesn't move), or does it appear to read too low or too high? With the engine fully warmed up, the needle should be roughly in the middle of the gauge.

I'd focus on the temperature gauge at this point, and worry about the "over-temperature" part of the circuit later. If the gauge is working correctly, you really don't need the over-temperature indicator since you can just look at the gauge as you drive.

-Bryan

[TeeCee]

Anyone know how to test the gauge. I'm buying a manual asap.

[18Fiatsandcounting]

Anyone know how to test the gauge.

Yes, although I have to admit this is for an earlier model year Fiat and may not be applicable to your '82. One at a time, ground the two leads that go to the temperature sensors in the cylinder head. If there is only one lead/sensor, that's OK, just ground that one. The temp gauge should go full scale when at least one of them is grounded.

But, I'll ask again: What is the gauge doing that makes you want to test it? The reason I ask is that I've never had a gauge that failed, and problems are almost always the electrical leads/connections or the temperature sensors.

-Bryan

[TeeCee]

The reason I want to check it is because you said look at the gauge at this point, lol.
I'm going to recheck to see if the gauge moves when I ground the sensor nearest the firewall. I didnt ground that one.
I may buy a Bosch gauge to use until I get the original looked at or if I figure out how to test the gauge.

[tima01864]

mirafiori.com, If you are looking for manuals and troubleshooting info. The site has an online libbrary one can access after registering to the page. I reccommend looking through the library and deciding on getting a hard copy of what you need.

[18Fiatsandcounting]

The reason I want to check it is because you said look at the gauge at this point, lol.

Sorry, I guess I was not clear. When I asked about what made you think the gauge was not working, I was thinking of when you were driving the car around. You already grounded the gauge at one point and the needle went full scale, so that tells me that the gauge is likely OK. But when you're driving the car around, does the gauge move at all?

I'm going to recheck to see if the gauge moves when I ground the sensor nearest the firewall. I didnt ground that one.

Let us know what you find out.

Just to make sure I'm not missing something here, your '82 does have two temperature gauge sensors screwed into the cylinder head, one sensor between plugs 1 and 2 and one sensor between plugs 2 and 3, right? My current Fiats are all much older than your '82, so my memory is weak on the later model years. There will be other temperature sensors that deal with things like fuel injection and emissions control, but I don't believe those have any effect on the gauge reading.

By the way, the temperature sensors do sometimes go bad. The first cause of problems is usually a loose connection, followed by the fuse to the instrument cluster, followed by a bad sensor, followed by a bad gauge. But that's just my experience, and your issue could be any of these.

-Bryan

[TeeCee]

Bryan, thanks, I think I'll change the sensor, see what happens, then go from there.
Thanks mira! I'll sure check that out for the manuals

[davidbruce]

On my 1980 the resister is in a blue holder. It is located near the gas pedal pivot on mine.

[TeeCee]

Thanks, I saw that holder. I will check it.

[TeeCee]

When I bought this car I knew it had cooling issues. Right off I found a leaking heater hose and replaced it.
Well I have noticed coolant collecting in the spark plug holes. The 2 rear ones are dry but the front 2 are still collecting coolant. After the engine warms it looks like the coolant is bubbling or leaking around the plugs.
This is a 82 Spider 2000
Let me know if you have a clue as to what's wrong. Thanks

I do still have the water bubbles or boiling in the plugs.
I made a video if I could post it I would