Hello,

So I'll describe everything I know as there seem to be multiple symptoms here that could be related or possibly not.

Not long after I first got the car one of the cylinders cut out briefly but then came back on. After the distributor failed I took this to have been a spark issue. Since then I replaced the distributor with a brand new OEM unit, along with the plugs, wires, and fuel filter.

I was also told when I took it in for inspection that there appeared to be a coolant leak. I topped up the coolant while waiting for the new distributor as well.

The car has run perfectly for 300+ miles since installing the distributor until this morning. It had run well until I parked for a brief 5 minute stop. When I came back and started it up, it was again on 3 cylinders. I also noticed a lot of exhaust fumes coming out, specifically when giving it the revs to get going in 1st gear.

Finally, a few blocks from my house I noticed the temp gauge creeping towards the red. It never got higher than about 3/4 of the way up and I never got a warning light. It began fluctuating between this point and the middle of the range as the cooling fan ran continuously. I've never noticed the cooling fan coming on that much before and usually the gauge stays about a 1/3 up from cold and has since I bought it.

After the car was sitting for about 90 minutes I came out and noticed a persistent hissing sound from under the rad cap (it's a new cap). I also cleaned off the dipstick and checked the oil which was extremely low (nothing on the dipstick), however no milky oil as I've experienced before on other cars.

Sorry for the verbose post but I wanted to be specific as to everything I know thus far. Any help is greatly appreciated before I dive into a major repair job.

 

When you heard that hissing sound, was the top radiator hard like a rock?

 

I didn't really get near the radiator, sorry. I figured it was still too warm to touch.

I just went to have another look at it. I put almost a litre of coolant into the radiator itself, but the expansion tank was still up to the proper level. So now I'm suspecting the radiator is the source of the leak. There was some fresh coolant accumulated on top of the cooling fan as well so maybe it's come out under the cap? It's a new cap but maybe not a very good one.

I also added a quart of oil to bring it just up to the bottom mark on the dipstick. That issue I think is just me being a bonehead forgetting to check it as some oil leaked out during the distributor change and I forgot to top it up. I'll monitor it more frequently now to see if there is an issue there.

The coolant in there is still green but somewhat discoloured indicated it needs to be flushed, which I was planning to do with a TB/WP change this summer anyways. And no milkiness in the oil it's still the proper colour.

So the radiator could explain the coolant loss, but then what about the loss of a cylinder and the accompanying white smoke during the episode?

 

If it was me I would do a pressure test on the coolant system to see it there is a leak. If pressure bleeds off and no signs of a leak, then I would do a leakdown test form there.

 

Your headgasket is bad, allowing coolant to leak into one of the cylinders while the engine is off. When you go to start it the coolant in the cylinder prevents proper firing, and that is why it is running on 3 cylinders. Once the coolant burns off the cylinder can fire again, usually within 10-15 seconds. The white smoke is the burning coolant.

I had this exact problem with my new engine. In my case I was losing small amounts of coolant but had to external leaks that I could see. I would start the car and it would run on 3 cylinders for a few seconds before returning to normal and running fine. After a headgasket replacement I have not had any problems. Also note that my coolant was not discolored and I did not have any white smoke during startup. Every car and situation is different but from what you describe it sounds like your headgasket is to blame. You could verify with a leakdown test, or just take the head off and replace the gasket like I did.

I suspect a bad radiator or cap is your hissing sound. Start the car and watch the engine bay as it gets up to temperature. Visually inspect all hoses and the radiator for leaking coolant. You want to be sure of what is leaking instead of buying parts you don't need to replace. It overheats because the leak allows for air bubbles and it isn't pressurizing the system properly.

 

ill 2nd the "pressure test your cooling system."

id hate to see another person mis-diagnose a head gasket when it could be just an external leak. exhaust all other options before diving ahead and replacing a hg

a few years back i had my mechanic friends tell me i needed a head gasket but i troubleshot the problem properly, pressure tested the cooling system, and all i needed was a 6" piece of hose that cooled the throttle body area..


good luck