Leak Down - 80% down via Exhaust Valves

[sacrileger]

Don't feel bad! It's happened to a lot of people then just don't post about it haha. Pull the head internals off and inspect everything. I'm willing to bet your valve guides are cracked too.

Yup, 4 guides cracked. One guide cracked in three places and was deformed. I find it impossible that this could be done by rotating the engine by hand or clipping the valves against the block as I was putting the head on. By looking at the pistons in post #16 and all that black oil over the piston head, I think some of it was preexisting. Some of the cracks did not look fresh..there was black oil and carbon in it.

 

[1990TSIAWDTALON]

Those dark cracks would be old. I replace guides on all my heads because they see positive pressure (and a lot of it). Sorry but it will all be good in the end!

 

[boostdawd]

Just recently had to refreshed up my cylinder head like you. Half my quides were cracked. 1 bad valve. Out the door was like 280. Pretty cheap if u ask me.

 

[sacrileger]

Just recently had to refreshed up my cylinder head like you. Half my quides were cracked. 1 bad valve. Out the door was like 280. Pretty cheap if u ask me.

$280 is a bargain. I just got a quote this morning to fix my head from a nearby machine shop that guarantees their work and I might have to go see my doctor first to find out if I suffered a mild coronary episode. The shop is asking $800 CDN before tax (15%) for 16 guides, valve job and resurface. At current exchange rates, that would be around 600USD (plus valves).

 

[livedsm4g63]

A normal valve job on a 4 cylinder head with 4 valves per cylinder is roughly $200 and a resurface should cost around $50. Im about to pay $250 for the things I just listed on a head of mine.
If you need new guides, bronze installs cost roughly $120.

These numbers come from a well priced performance shop in the greater Detroit area.

 

[sacrileger]

A normal valve job on a 4 cylinder head with 4 valves per cylinder is roughly $200 and a resurface should cost around $50. Im about to pay $250 for the things I just listed on a head of mine.
If you need new guides, bronze installs cost roughly $120.

These numbers come from a well prices performance shop in the greater Detroit area.

Thank you. I searched this site and your quote is comparable to everybody else's. I am not prepared to spend $600 USD. I am calling and getting quotes from other machine shops until it's within reason.

 

[boostdawd]

For what it's worth...dacowgod had a couple of heads for sale for less than 400. Just a thought. The machine shop quote is a bit high in my opinion.

 

[AdR]

The last head I payed to get done (new cams, valve angle job, new guides, seals, shimmed for solid lifters, cleaned and decked) cost me $250... $600 is not a little high, it's ridiculously high.

 

[gsxeclipse102]

I payed 750 for my last head work. Port and polish, bronze valve guides, 1mm os valves intake and exhaust, egr port closed up, cbn resurface, new exhuast studs installed, cleaned and assembled. For standard valves with no port work i wouldnt pay over 350

 

[Twizted99GSX]

im about to get my head worked on and I am contemplating getting Bronze Valve Guides. That's 150 Plus Guides 65, a valve Job 250 and Resurfacing 75. I was told I needed all new Valves since the head I got is Not the head they came out of, that I cant use the old valves but I thought a valve job made the old used valves seat and work properly.. and Possibly new springs If im not bankrupt after this .. But my Question is what's the need for bronze valve guides.. whats the added value? just curious before I put them in.. And can I use my other heads Valves in the new Used head with a valve job.. or am I getting the BUSINESS... Thanks for the Help DSM FAM..

 

[motomattx]

I dont reccomend bronze guides on any engine not being used soley for racing with frequent tear downs. The advantage of them is lower friction, the cost is that they are much softer than the valve material and will wear much quicker. Yes, if your used valves are within specs AFTER you have them refaced and checked for straight then you could re-use them

 

[Twizted99GSX]

Ok I cleaned the valves with Carb Dip and wire wheeled all the carbon and crap on them down to normal they look like new almost but should they be refaced too or? Thanks for the Knowledge. I read this entire thread and glad I did, I wont bend valves now... Well at least ill try not to...


"Give a person food they eat for a day--- Teach a person how to Hunt and Fish they will eat for life..."

 

[motomattx]

Yes, they should always be refaced, even an experienced tech has a hard time telling by looking if a valve face is in good shape or not.

 

[Geeb]

I just lapped all my valves. Def get on that. You can do it in no time with a 1/4" drill Chuck adapter and the small suction cup off an oem lap tool, stick it on the Chuck, get some valve lapping compound, and go to town. Sealed mine like a champp

 

[motomattx]

Machine shops charge a minimal amount to professionally reface a valve and square up the stem, and usually charge nothing for ones that arent able to be refaced, mine charges like $2 or $3 each.

 

[Geeb]

Machine shops charge a minimal amount to professionally reface a valve and square up the stem, and usually charge nothing for ones that arent able to be refaced, mine charges like $2 or $3 each.

Mine is about 5 or 6 each I think.. For one or two not bad, but it adds up at 16

 

[motomattx]

The best $80 you will spend on your car period, otherwise you risk all kinds of random running and drivability problems that mask themselves as other things.