[twinmill28]

Ok, you guys did a stelar job guiding me to putting my wife's 91 Daytona back on the road with new lifters and timing belt and all new rad and heater hoses.
I'm still trying to sort out a rough idle when it warms up and sits at a stop light (automatic, in gear). It's throwing a 35 code, so I need to look at that connector going to the temp sensor (I replaced the sensor while working on the cooling system as well).
Anyway, other than that rough idle, that car is running like a raped ape (that's a good thing in this case). But I've been keeping an eye on the coolant and adding ALOT. I haven't found any in the oil, it's still nice and clean from a recent change. I'm not finding any of the new hoses leaking (tightened one tiny drip up), and it doesn't look like there's any visible signs of it going anywhere. There's been some seepage noted on the head to block on the front and I've been keeping an eye on it.
So the big question is where's my coolant going??!

 

[John Wood]

When is the last time you had a look at the spark plugs? Check for 1 or 2 that are different from the rest which might indicate antifreeze being vaporized in the combustion chamber. For a headgasket leak, you may not always see contaminated oil, but sometimes you can detect bubbles in the overflow container at certain engine temperatures (with the engine running) and see a steam cleaned spark plug that will differ from the others.
Ocassonal white smoke out the tailpipe on a warmed up engine may be another clue to a HG leak.

Hopefully, it is just air being displaced from having the system open. How has the temperature gauge been acting?

 

[george w]

Take a close look at the radiator overflow bottle when the engine's running. You should see a shimmer in the water surface from engine vibration but no bubbles. Bubbles = head gasket failure.
The symptoms of coolant loss and rough idle point to headgasket but a compression check is easy enough to do. If the HG is bad then you'll probably want to change the oxygen sensor once the head gasket is replaced if the idle is still rough.

 

[Scstables]

Heater core leak? I was losing antifreeze because the heater core was leaking on my daytona. I recently had that fixed, and the garage charged me extra because you have to remove the entire dashboard to get to the stupid heater core (which costs like $50.00). The entire bill which I know is reasonable came to $409.16 (I her some places charge a lot more than this to do this job). Now, my heat comes on quickly and no funky smell or steamed up windows. Yay!

 

[twinmill28]

I just had a buddy look at it for me, we removed the rad cap got the engine warm and running and watched bubbles coming up thru there. He told me it's a sure sign of a bad head gasket, then when I checked this post for responses, that's pretty much what you guys are saying.
So now the question is where to get a head rebuilt around this town? I may have to go to Pensacola, I've got a friend who's really doubtful of the skill of any local shops. What are the odds of getting a head that's already built?
Another question of course is, what are my upgrade upgrade options for performance? With just under 80K on the odo (okay, it's at 127,000 kilometers) I think I have some room for improvement.
Also, can I reuse the new lifters I just installed, or drop another 50 bucks for a new set? How about the cam? Reuse, or get something a little hotter or just go back to stock?
How long does it take to pull a head and put back on? This one's never been off, I can imagine getting the exhaust bolts off are going to suck.

 

[twinmill28]

Found a site on the internet, Cylinder Heads International that will ship out a complete rebuilt head with cam and lifters for $220. They don't take an upfront core charge, but give you 30 days to send them your junk or they will then hit you with a core charge. Have any of you guys dealt with this company? They claim to have been in business since '68.
It doesn't sound like a bad deal, but I don't want to keep swapping heads out every six months if I end up with somebody else's rebuilt junk. The warranty is for a year, which is ok, but really, I don't want to keep swapping heads!

 

[Bob Lincoln]

If the engine hasn't overheated, then the head is almost certainly fine and won't need replacement or rebuild. Just replace the head gasket, after checking the head for flatness (.004" or less across its span). I had this same failure last year, and did the head gasket myself. Being a novice, and taking time to clean the head and pistons with solvents, and changing out the timing belt (a first for me), I spent about 12 hours total. However, it could easily have been 8 or less. Some people here can do it in 5-6 hours. Make sure to replace the timing belt, since it has to come off, anyway. And always use new head bolts, they are torque-to-yield, so they are already stretched by definition when they are removed. A new set is about $20-$40.

As for the exhaust bolts, leave the intake and exhaust manifold attached to the head, and cut the bolts that attach to the down pipe. Auto parts stores sell a bolt kit that includes the springs and washers for about $15-$20. The donut gasket is about $8. If you have access to a Dremel tool with a cutoff disc, the bolts can be cut off from below in about 10 minutes or less.

A/C compressor has to be unbolted from the bracket and swung aside, but the A/C system does not have to be opened.

 

[george w]

I agree that you very well may not need a new head. If the head is flat and not warped just clean things up and install a new HG.
You may see small hairline cracks between the valve seats. These can be ignored.