Plenum Pull Q's - ZR-1 Net Registry Forums

tomtom72 · 08-11-2007

Hi guys,

I should know this but I'm old & senile & I forgot!

If you have to pull the plenum you should wait for the motor to be stone cold, right????

I know it's a stupid Q. I rent a garage to keep my Z and I have to drive to it to do any work on the car. It's not that far but by the time I get there I'm about 1/2 way on the temp gauge. So I'm thinking that I should not work on her till the coolant is cold to the touch, right???

Thanks,
Tom

cuisinartvette · 08-11-2007

I feel your pain, I have to drive across town to a garage I keep mine at too. What a PITA if you forget tools....Guess thats why mine has sat for so long.

Id drain some coolant from the pitcock on the radiator before pulling it off. Plenum will be warm to the touch for a bit.

Aurora40 · 08-11-2007

I'd think it would be more for your sake than the cars, though. I imagine you could pull it off warm and it would be fine, if your hands can stand it.

Why do you have to go under there again?

tomtom72 · 08-11-2007

Thanks Ron & Bob! I seemed to think I remembered an old time wrench telling me never to dis-assemble a hot motor????

Ron, I feel your pain. We should start a club for homeless ZR-1's. Forgetting tools is the least of my problems. My Z is my only car now so if I don't bring it, it don't get dunn!

Bob, I got a SES light the other day & it turned out to be 61, 2* trouble. My scanner will not do all the tests that a Tech1A does so I had no choice but to do the flow chart without doing the required functional test. And.....after all that it turned out to be the ECM!

Well at least I passed my refresher course on plenums 101....it was easier the second time around! But I look on the bright side, at least I confirmed that my CCVB cover no longer leaks!

Well time for a shower & a good test drive.....it's a good thing that I have bad luck with vettes & keep a small cashe of spare parts!

Tom

tomtom72 · 08-12-2007

Test drive report:

I now have a vette again, not some car that just looks like a vette!

08-12-2007

Tom, keep in mind all the pieces are aluminium and they get a little softer when warm.

Norsky4360 · 08-13-2007

I'd wait until it has cooled down enough for the coolant pressure to be almost gone. Then crack the expansion tank cap to relieve the rest of the pressure.

When I was doing my 'very last first' plenum pull someone shared a tip to drain the coolant from the expansion tank rather than drain everything via the radiator. Naturally I saw that after I'd already drained the radiator. I'll have to dig a little to find it.

tomtom72 · 08-13-2007

Thanks guys. Yea what I did was some other stuff that was bothering me and by the time I was dunn there was no psi left in the coolant sys. & the coolant was just barely warm to the touch. Man these motors retain heat for awhile!

Jeff, I should remember that for the future! I was thinking that there was a slight chance of having things warp if I started to take stuff apart while still too hot. That's what kills me about the diagnostic charts in the 6E section.
"Scan motor in closed loop, does the scan report 2* vac @ .74v? Yes, pull plenum and test connector @ solenoid by shorting A & B leads."

Some non- trained backyard type like me sees that & thinks "how long do they wait to pull the plenum"? But I fixed the rattle from my front calipers and then tackled the plenum!

I should have swapped the ECM 1st just for sh*ts & giggles and I could have saved the labor. I think I learned something. The rapidity at which the DTC re-set itself should have tipped me to an electrical issue. I would clear it using the scan tool and it wouls re-set within 5 seconds. Oh well.

Hey, do we all know anyone reliable that repairs ECM's????

Tom

Belsy · 08-13-2007

Many years ago a friend pulled his dual quad system off while warm and it warped so bad he could not re-use even after planing the surfaces.
WAIT and enjoy the result!!

Belsy · 08-13-2007

On this note, what is the concensus on coolant by-pass on plenum & throttle body??

08-11-2007	#1
tomtom72 Join Date: Dec 2004 Location: Jacksonville, FL USA Posts: 4,609	Plenum Pull Q's Hi guys, I should know this but I'm old & senile & I forgot! If you have to pull the plenum you should wait for the motor to be stone cold, right???? I know it's a stupid Q. I rent a garage to keep my Z and I have to drive to it to do any work on the car. It's not that far but by the time I get there I'm about 1/2 way on the temp gauge. So I'm thinking that I should not work on her till the coolant is cold to the touch, right??? Thanks, Tom __________________ 1990 ZR-1, Black/grey, #2233, stock. ZR-1 Net Reg Founding Member #316 & NCM member

08-11-2007	#2
cuisinartvette Join Date: Aug 2005 Location: San Fernando Valley, CA. Posts: 896	Re: Plenum Pull Q's I feel your pain, I have to drive across town to a garage I keep mine at too. What a PITA if you forget tools....Guess thats why mine has sat for so long. Id drain some coolant from the pitcock on the radiator before pulling it off. Plenum will be warm to the touch for a bit.

08-11-2007	#3
Aurora40 Join Date: May 2005 Location: Leesburg, VA Posts: 2,704	Re: Plenum Pull Q's I'd think it would be more for your sake than the cars, though. I imagine you could pull it off warm and it would be fine, if your hands can stand it. Why do you have to go under there again?

08-11-2007	#4
tomtom72 Join Date: Dec 2004 Location: Jacksonville, FL USA Posts: 4,609	Re: Plenum Pull Q's Thanks Ron & Bob! I seemed to think I remembered an old time wrench telling me never to dis-assemble a hot motor???? Ron, I feel your pain. We should start a club for homeless ZR-1's. Forgetting tools is the least of my problems. My Z is my only car now so if I don't bring it, it don't get dunn! Bob, I got a SES light the other day & it turned out to be 61, 2* trouble. My scanner will not do all the tests that a Tech1A does so I had no choice but to do the flow chart without doing the required functional test. And.....after all that it turned out to be the ECM! Well at least I passed my refresher course on plenums 101....it was easier the second time around! But I look on the bright side, at least I confirmed that my CCVB cover no longer leaks! Well time for a shower & a good test drive.....it's a good thing that I have bad luck with vettes & keep a small cashe of spare parts! Tom __________________ 1990 ZR-1, Black/grey, #2233, stock. ZR-1 Net Reg Founding Member #316 & NCM member

08-12-2007	#5
tomtom72 Join Date: Dec 2004 Location: Jacksonville, FL USA Posts: 4,609	Re: Plenum Pull Q's Test drive report: I now have a vette again, not some car that just looks like a vette! __________________ 1990 ZR-1, Black/grey, #2233, stock. ZR-1 Net Reg Founding Member #316 & NCM member

08-12-2007	#6
Jeffvette Guest Posts: n/a	Re: Plenum Pull Q's Tom, keep in mind all the pieces are aluminium and they get a little softer when warm.

08-13-2007	#7
Norsky4360 Join Date: Feb 2007 Location: Colorado Posts: 115	Re: Plenum Pull Q's I'd wait until it has cooled down enough for the coolant pressure to be almost gone. Then crack the expansion tank cap to relieve the rest of the pressure. When I was doing my 'very last first' plenum pull someone shared a tip to drain the coolant from the expansion tank rather than drain everything via the radiator. Naturally I saw that after I'd already drained the radiator. I'll have to dig a little to find it.

08-13-2007	#8
tomtom72 Join Date: Dec 2004 Location: Jacksonville, FL USA Posts: 4,609	Re: Plenum Pull Q's Thanks guys. Yea what I did was some other stuff that was bothering me and by the time I was dunn there was no psi left in the coolant sys. & the coolant was just barely warm to the touch. Man these motors retain heat for awhile! Jeff, I should remember that for the future! I was thinking that there was a slight chance of having things warp if I started to take stuff apart while still too hot. That's what kills me about the diagnostic charts in the 6E section. "Scan motor in closed loop, does the scan report 2* vac @ .74v? Yes, pull plenum and test connector @ solenoid by shorting A & B leads." Some non- trained backyard type like me sees that & thinks "how long do they wait to pull the plenum"? But I fixed the rattle from my front calipers and then tackled the plenum! I should have swapped the ECM 1st just for sh*ts & giggles and I could have saved the labor. I think I learned something. The rapidity at which the DTC re-set itself should have tipped me to an electrical issue. I would clear it using the scan tool and it wouls re-set within 5 seconds. Oh well. Hey, do we all know anyone reliable that repairs ECM's???? Tom __________________ 1990 ZR-1, Black/grey, #2233, stock. ZR-1 Net Reg Founding Member #316 & NCM member

08-13-2007	#9
Belsy Join Date: Nov 2006 Location: DeBary , Fl. Posts: 119	Re: Plenum Pull Q's Many years ago a friend pulled his dual quad system off while warm and it warped so bad he could not re-use even after planing the surfaces. WAIT and enjoy the result!!

08-13-2007	#10
Belsy Join Date: Nov 2006 Location: DeBary , Fl. Posts: 119	Re: Plenum Pull Q's On this note, what is the concensus on coolant by-pass on plenum & throttle body??