No good deed ever goes unpunished

[TommyClocks]

Well, I installed the timing belt, thermostat and recored the radiator. I burped the system and allowed the temp to reach about 185 and the thermostat opened just fine. I took the car off the ramps and filled the cooling system the rest of the way. The motor ran very smoothly during the "burping" process. I was thinking "not bad for my first timing belt". The next night I took the car for a test drive and the car ran fine for about 30 minutes and then it seemed to lose power, so I drove it home. The next morning I had trouble starting it and decided to leave it alone until after Thanksgiving. I worked on the car yesterday and checked compression. Cylinders 1 & 4 read 98, cylinders 2 & 3 read 30 and I can hear air hissing from the carb when I crank the motor by hand. I checked the cam timing and all 3 marks are in the right place. I can see the valves open and close when I look through the spark plug holes. I wonder if the head gasket went south? I'll remove the cylinder head tomorrow night and see what I find. Sorry I missed the "Turkey Trot" today, hope you guys had some good weather.

Tom

[Daniel]

Sorry to hear that Tom sometimes these older cars have kinks that need to be worked out before they can
be enjoyed ! hang in there .

[TulsaSpider]

Those numbers are incredibly low, you definitely have an issue!

[majicwrench]

As you have surmised, you likely have head gasket blown between 2 & 3. Could be just time for it to fail, but would not suprise me if perhaps it pinged and thus the failure.
At least it is an easy head gasket to do!

[james124]

Can you give us a bit more background info on the condition of the engine, age, mileage, recent rebuilds, mods etc. Odd that the car was driving fine and within half an hour looses that much compression. Have you noticed any other signs of a blown gasket... white smoke, black pugs, low oil, low coolant, oil in coolant and vice versa. I guess what what I am saying is make sure before you pull off the head. Good luck and keep us tuned-in. JimmyG

[v6spider]

I would suspect whatever work you did last before assuming some other problem. First did you make sure that you were on TDC on cylinder number one? If the marks were aligned and you were not on the compression stroke on the number one cylinder then you could be 180 degrees out on your cam timing. Even with a blown head gasket I don't think it would spit air back into the carb... sounds more like cam timing to me...way to check is to get it on TDC on cylinder number one. Then check the marks.

[TommyClocks]

I was itching to know what went wrong with my car so I removed the cylinder head. I was afraid I had done something wrong when I changed the timing belt. It turns out that the head gasket was bad for sure but the strange thing is that it blew out right after changing the belt. It looks as if it had been going bad for a while.... Here are some pics.

I would like to clean the valves and tops of the pistons, anyone have suggestions on what to use. Scotcbrite, chemicals?

I also noticed the master cylinder leaked, so it will be easier to change now because I have more room to work. With a little luck we may be back on the road soon.

http://www.flickr.com/photos/tommyclocks/5217258916/

http://www.flickr.com/photos/tommyclocks/5216670765/

[TommyClocks]

I am very cautious when I perform a fix for the first time. I often check and recheck my work, here are the pics of the cam timing, it looks correct when I compare it to the Fiat manuals.
http://www.flickr.com/photos/tommyclocks/5216713237/
http://www.flickr.com/photos/tommyclocks/5216713077/
http://www.flickr.com/photos/tommyclocks/5217301552/



It is very strange that the head gasket failed after the timing belt replacement, but I am not going to worry too much about it. Like Keith said, maybe it was just its time to fail. I'll let you know how it goes when I get the car back together..........I really love driving this car......

[baltobernie]

Sorry to hear of your misfortune, but it looks like you've got a methodical repair process in place. You'll be back on the road in no time. You might want to check the level in your steering box and adjust steering play while the head is off; lots more room in there now.

[majicwrench]

Well, I did say it could just have been the head gaskets time to fail, but I also mentioned it could have been pinging and thus the failure.
You can clean pistons/ valves if you so desire, but there is really no need unless some sort of huge buid-up. I would just gently scrape it away. Carb cleaner will help loosen it. Vacuum out cylinders. Wire wheel valves.

Make darn sure that blown area is not worked into the block surface or head. Does not sound like yoiu have run it much after the failure, so it should be OK, but check. Clean out head bolt holes, clean head bolt threads.
Tis gonna run again soon!

[v6spider]

I would have the head surfaced by your local machine shop. Certainly is coincidental that your gasket blew. However if you want it to seal I HIGHLY recommend getting it surfaced chances are the head is warped and that is what caused the gasket to blow. It isn't expensive and it would help to have the machine shop take a look at it and make sure there are no other problems. If you just put a new gasket on it will blow again for sure. Head gaskets don't blow for no apparent reason or because of a timing belt change. Any way just my two bits...

Rob

[majicwrench]

I respectfully disagree about surfacing it just because. CHECK IT, if warped or damaged, then surface it. Once you shave material off the head, your cam timing changes, your compression changes. When ever I get a head surfaced, I measure a few stragic place so I know how much material they are really shaving off. I probably do 6-7 hd gaskets a year here in the shop on various makes, and probably only surface 2. Come to think about it, I have not had one surfaced yet this year. Still a month to go though, and I do have a Toyota in lot right now blown between 3&4 waiting to come apart.

Scary taking stuff to machine shops too, just like any other shop, or any other human, they can have a bad day and damage stuff.
Your head did not suddenly warp from the T belt job.
Warp.....block is really sturdy, head is flexable. Small warp not big reason for concern. ANY WEAR IN THE AREA TWEEN CYLINDERS IS BIG REASON FOR CONCERN!!!
Yes, gaskets can blow for no reason. Block is iron, head is aluminum, they expand at different rates, gasket is getting stressed every time engine heats up or cools down.

PINGING is possible culprit here. It really stresses gasket. Slight changing in ignition timing could cause it.
Good luck!
Keith

[majicwrench]

Couldn't find a warp spec in any of my aftermarket Fiat manuals. Just grabbed a Factory Toyota 22RE ( 4cyl alum head) manual, the maximum warp is .0059 in.

[ventura ace]

My Fiat 124 Spider Shop Manual suggests .002" maximum variation from flat.

Alvon

[wikkid]

Sorry, I didn't follow all the above replies, I just stopped right when I heard the word "Scotchbrite" used right next to "to clean the pistons." There is aluminum oxide (abrasive) in Scotchbrite pads, and you really, really don't want to leave any abrasive residue inside your cylinders. So I vote no on the Scotchbrite treatment. The tops don't look dirty enough to worry about in your photos. I'd stuff some rags down into the cylinders to catch runoff, and use gasket remover liberally on the top surface; ditto on the mating head surface. Lots of gasket gook on there. You want to remove it really gently - no scoring of the surface, and again, no scotchbrite abrasive stuff. It takes patience more than anything. I've tried brake cleaner, I've tried that goop-off general cleaning remover stuff - you just need to work it in and give it time to do its stuff. Also, it's important to use a criss-cross star pattern in evenly tightening down the head when you go to re-assemble. It's easy to warp aluminum parts when you over-tighten one area unevenly.