Alfa Romeo Forums banner

1 - 14 of 14 Posts

·
Registered
Joined
·
2,177 Posts
Discussion Starter #1
So after some mildly panicked diagnosis, I have a dangling intake valve seat in my #1 cylinder. The head will definitely have to come off and at the very least the valve assembly will have to be replaced. I'll do as much as I can, but with the blown seat I've been reading that machining is almost certainly in the cards.

Although my resources are limited right now (both money and time) I don't want to miss something and have to jump back into engine work.

My compression seems fine (got 150 PSI across the board, other than #1 of course, on a totally cold engine) and I'm just trying to track down a gauge set so I can do a full leakdown test. But should I plan to pull both heads and replace all of the valve seals? Pull and clean all of the valves? Water pump? Any advice or suggestions will be appreciated!

Also, does anyone have advice on compressing the valve springs if I don't have access to the official Alfa tool, and also the tool for retaining the camshaft for removal.
 

·
Premium Member
Joined
·
13,982 Posts
Has it really dropped the seat? Richard Jemison discussed seat replacement recently and said that it should only be done by someone who is very competent. He said that Jim Steck is the only person that he would entrust it to.
 

·
Registered
Joined
·
2,177 Posts
Discussion Starter #3
I won't know for absolutely positively certainly sure until the head comes off, but I don't know what else it could be. The photo I was able to provide wasn't the best image I got, but I could clearly see the ring-shaped seat protruding about 1/8" out of the head. Looking at the engine diagrams in the shop manual, that's the only possibility.

Soooo... great.
 

·
Registered
Joined
·
2,177 Posts
Discussion Starter #5
It's a 2.5.

I'm going to hold off on anything until I get the head off. I'm just curious as to approach since the head is coming off, regardless of whether it's a valve, a valve seat, piston, rings, etc. If you had to pull a head and tear it down, even somewhat, for a significant repair, what else would you consider priority while it's apart? What else should I be looking for and considering? That's really what I'm asking. Not how to I repair the problem I haven't even fully diagnosed. Sorry if I wasn't really clear about that. Trying to keep the horse ahead of the cart here.
 

·
Registered
Joined
·
264 Posts
new timing belt and water pump whilst in there...

New valve stem seals if you have smoke on throttle lift off. Check valves for pitting etc and replace as needed. Check valve springs. Check oil passages. Reface the head if there is and pitting etc...

Just what I can think of on the fly.
 

·
Registered
Joined
·
4,330 Posts
...... If you had to pull a head and tear it down, even somewhat, for a significant repair, what else would you consider priority while it's apart?

What else should I be looking for and considering?
If pulling head(s) everything should be assessed. Getting head removed involves removing air/fuel delivery system (how old are fuel hoses? etc). Look for evidence of uneven combustion, cracking, heavy corrosion or pitting, major blemishes in combustion chamber and gasket surfaces. Be critical - now is the time to be. If your injectors are the least bit suspect it is very wise to have them all ultrasonically cleaned. Very inexpensive and really improves the feel of the car. Fuel Injector Connection in GA is the best I've experienced with this service. World class and really good prices.

As others have said, timing belt/tensioner and water pump for sure. If it were me I'd be doing ALL seals, guides w/ manganese bronze. Cheap and wise insurance, any competent machine shop can do. Valves are also pretty inexpensive and modern stainless/other variants are more reliable than the originals. Check cam lobes for wear, and tappets. It's not uncommon to find pitting on your exhaust tappets - replace them. They can't be repaired. All head gaskets and seals should be renewed (head gaskets, intake runner gaskets, spark plug well seals, fuel injector seals, etc.).

These jobs seldom end with work limited to original plans. It usually develops (for the better) into additional work to ensure reliable operation in future. For the labor involved, having a truly fresh engine at the conclusion is a very good feeling indeed - and it's only a few hundred bucks more in many cases.

I doubt your head failed a seat. I wouldn't be surprised if the valve itself failed or if a guide partially failed and is blocking valve from closing/caused it to bend. You mentioned car would hesitate - it is possible that the valve lash was too loose and the valve actually stretched and then failed. A stretched valve would cause poor running. If you have a hole or other visible damage to your piston you may want to consider looking for another 2.5 or a 3.0 to swap in...

Good luck
 

·
Registered
Joined
·
2,177 Posts
Discussion Starter #10
Thanks for all the recommendations.

So if I'm pulling one head, I'd might as well put in the extra effort to pull them both? Despite your warnings about the back wrenching work involved.

Realistically, I guess that depends on what I find when I get the know bad one removed. If everything in #1 looks thrashed, I might very well be looking for full replacement options. I already have a spare transaxle that I one day hope to rebuild. Why not add an engine to the wishlist?
 

·
Richard Jemison
Joined
·
7,370 Posts
Engines

If you have head issues, I have 2 or 3, 2.5 engines that you can have for comming and getting them. That`s the cost, you have to take all of them!
Cams are out of all the motors as used as cores....)

There is a early (Verde) 3.0 that I bought and never used. Complete (less cams). $600.00
 

·
Registered
Joined
·
2,177 Posts
Discussion Starter #13
If you have head issues, I have 2 or 3, 2.5 engines that you can have for comming and getting them. That`s the cost, you have to take all of them!
Cams are out of all the motors as used as cores....)

There is a early (Verde) 3.0 that I bought and never used. Complete (less cams). $600.00
Road trip to Pensacola? Maybe I can find someone coming to Austin for SXSW in a couple of weeks?

Hmm. I want a 3.0. Honestly though, how hard is the transplant? Research time.

Over ambitious? And I still don't know EXACTLY what's wrong with mine yet.
 

·
Registered
Joined
·
1,840 Posts
You really should do the swap with the Verde unit, as the performance boost is great and its a direct fit. Swap with a 164 unit is a bit more complex.
 
1 - 14 of 14 Posts
Top