3vzfe leakdown test numbers

blumista2 · 07-16-2009, 04:38 PM

Hello Everyone,

Quick intro, I'm new to this board, but have been active in other mr2 boards... Anyway, I've just recently leakdown tested my 3vzfe... it had 240K mi at the time it was pulled from my donor. My leakage percentages ranged from 10 - 15%. The most leakage (surprisingly) was in the intake valves. There was alot more air coming up and out from the intake ports compared to the exhaust ports. With those numbers, would the intake valves/seats, need attention?

I don't intend on any type of forced air induction... I want to keep it n/a. Track days... most likely... but it would be my daily driver for the most part. I do plan on refreshing the motor - have it hot tanked, new pistons, rings, gaskets, bearings, etc.

Jason.MZW20 · 07-17-2009, 05:06 PM

Could be a ton of carbon buildup on the intake valves. That would make the valves unable to close completely since it forms around the seating area. The stem seals are also probably shot to hell after 240k miles.

You can either have a valve job done or replace all 24 valves. Look into pistons with a moly resin coating on the piston skirt. This will increase the longetivity of the piston and reduce the wear on the cylinder walls. Some of my old 5SFE pistons have a lot of vertical scratching on this part of the piston, but my 1MZ pistons looked brand new.

blumista2 · 07-22-2009, 03:18 PM

Cool... thanks!

A couple more questions though, if I replaced all 24 valves, would I need to purchase new valve seats too? If I go this route, will I still need to have the new valves cut/grinded down to match the new valve seats?

4v6 · 07-23-2009, 05:08 AM

You wont need the valve seats in the heads replacing.
You wont need the valves replacing unless the stems are badly worn or some other defect is present like a bent/burnt out/cracked one.
Just about any performance oriented business should be able to dress the seats in the head and the valves and itll work out a sight cheaper than replacement of the items themselves.

blumista2 · 07-23-2009, 04:28 PM

Quote:

Originally Posted by 4v6

You wont need the valve seats in the heads replacing.
You wont need the valves replacing unless the stems are badly worn or some other defect is present like a bent/burnt out/cracked one.
Just about any performance oriented business should be able to dress the seats in the head and the valves and itll work out a sight cheaper than replacement of the items themselves.

Sweet... thanks! Once I pull the heads off I can visually inspect them, but no real way to tell until its been hot tanked and inspected. One more question, When you "dress the seats" did you mean lapping them?

07-16-2009, 04:38 PM	#1 (permalink)
blumista2 No Skills Join Date: Jul 2009 Posts: 3 Thanks: 0 Thanked 0 Times in 0 Posts iTrader Rating: (0/0% )	3vzfe leakdown test numbers Hello Everyone, Quick intro, I'm new to this board, but have been active in other mr2 boards... Anyway, I've just recently leakdown tested my 3vzfe... it had 240K mi at the time it was pulled from my donor. My leakage percentages ranged from 10 - 15%. The most leakage (surprisingly) was in the intake valves. There was alot more air coming up and out from the intake ports compared to the exhaust ports. With those numbers, would the intake valves/seats, need attention? I don't intend on any type of forced air induction... I want to keep it n/a. Track days... most likely... but it would be my daily driver for the most part. I do plan on refreshing the motor - have it hot tanked, new pistons, rings, gaskets, bearings, etc.

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07-17-2009, 05:06 PM	#2 (permalink)
Jason.MZW20 Pig Snout Join Date: Jul 2006 Location: Victorville, CA Posts: 1,373 Thanks: 15 Thanked 111 Times in 102 Posts Blog Entries: 6 iTrader Rating: (2/100% )	Could be a ton of carbon buildup on the intake valves. That would make the valves unable to close completely since it forms around the seating area. The stem seals are also probably shot to hell after 240k miles. You can either have a valve job done or replace all 24 valves. Look into pistons with a moly resin coating on the piston skirt. This will increase the longetivity of the piston and reduce the wear on the cylinder walls. Some of my old 5SFE pistons have a lot of vertical scratching on this part of the piston, but my 1MZ pistons looked brand new.

07-22-2009, 03:18 PM	#3 (permalink)
blumista2 No Skills Join Date: Jul 2009 Posts: 3 Thanks: 0 Thanked 0 Times in 0 Posts iTrader Rating: (0/0% )	Cool... thanks! A couple more questions though, if I replaced all 24 valves, would I need to purchase new valve seats too? If I go this route, will I still need to have the new valves cut/grinded down to match the new valve seats?

07-23-2009, 05:08 AM	#4 (permalink)
4v6 http://www.Typ-85.co.uk Join Date: Jun 2007 Posts: 184 Thanks: 2 Thanked 24 Times in 14 Posts iTrader Rating: (0/0% )	You wont need the valve seats in the heads replacing. You wont need the valves replacing unless the stems are badly worn or some other defect is present like a bent/burnt out/cracked one. Just about any performance oriented business should be able to dress the seats in the head and the valves and itll work out a sight cheaper than replacement of the items themselves.