very strange on 2001

[carl B]

whilr driving along with air con is fine. When you get on the gas and nail it you get hot air coming in through the screen vents. Let off and all is well again???

Tested out the ABS with three real hard stops. then when we set off the exhaust smoked for around 30 seconds????

Any thoughts please???

Carl

 

[Neil - UK]

your A/C is fine its normal for a viper, power is diverted away from the A/C under hard accleration but then as rev's smooth out A/C returns

smokey exhaust is also normal after your hard braking testing, it's engine oil getting dumpped into the intake under hard deceleration. No need to do anything about unless you plan to track the car

http://vca2.viperclub.org/forums/showflat.php?Cat=&Board=UBB14&Number=389967&Forum=UBB14&Words=oil%2C%20intake&Match=And&Searchpage=0&Limit=25&Old=3months&Main=389439&Search=true#Post389967

have you got it loaded up and homeward bound yet ???

 

[carl B]

set my mind at rest!!!

Trying to find a company to ship it now?

Carl

 

[luc]

Nothing to do with the power to the A/C, it's simply vaccum related.

Step ******* the gas, intake vaccum go down and vaccum operated flaps close.

Do a search, there are a couple of cheap and easy ways to solve this problem.

Luc 00GTS

 

[Steamroller]

Carl,

I previously posted the same question... and I received a great answer. Here is the link the Q&A:

http://vca2.viperclub.org/forums/showflat.php?Cat=&Board=UBB14&Number=440281&page=31&view=collapsed&sb=5&o=&fpart=1

 

[Vic]

Carl, your valve covers vent into the air cleaner box. If you put a puke can on the aluminum cross-brace, and run your breather tubes into the puke can, you won't ingest oil under hard braking. Some people move the breather vents to the top of the valve cover, so oil can't slosh out at all. If you regurgitate oil and step on the gas, the engine will knock until it clears up, so don't lean on the gas until it clears, as it could damage the engine. If you road race your car, its one of the first things to do to get your car prepped for the track.

 

[C O D Y]

It's the computer doing it. It is designed to do it and it is normal. WOT shuts the AC off.

 

[Randy]

No, you are NOT supposed to get hot air from the A/C when you step on the gas. I'm not sure who keeps passing this bit of misinformation around (other than the fact that most vipers do indeed seem to do this). Nothing disengages the A/C clutch (you know this is true, as there is no way it would get hot that fast), its just a matter of the reduced vacuum not holding the ventilation flaps in position.

As I recall, Herb Helbig even responded to a letter in the Viper Magazine earlier this year saying it should *not* do that, and that the fix was to replace the vacuum check valve. Now, I confess I couldn't find the vacuum check valve mentioned anywhere in my shop manual (although I since think I saw it behind the radio on my 2000 RT), but, before I found it, I just added a $5 vacuum check valve on the vacuum line coming off the left valve cover (which is indeed where the ventilation system gets it vacuum), and it works like a champ - no more hot air under throttle.

 

[luc]

Randy,

The A/C clutch do get "de-energized" at WOT but that is not the problem, the real problem is indeed vaccum related.

Luc 00GTS

PS: the a/c clutch is always cycling off and on to respond to line pressure and/or temperature but it will take a few minutes after the clutch is off, for the air to get warm/hot and it will be a gradual change in temperature.

 

[FE 065]

Carl, your valve covers vent into the air cleaner box. If you put a puke can on the aluminum cross-brace, and run your breather tubes into the puke can, you won't ingest oil under hard braking. Some people move the breather vents to the top of the valve cover, so oil can't slosh out at all. If you regurgitate oil and step on the gas, the engine will knock until it clears up, so don't lean on the gas until it clears, as it could damage the engine. If you road race your car, its one of the first things to do to get your car prepped for the track.

FWIW, I modified an OEM oil fill cap to vent to atmosphere without losing oil using a plastic pipe fitting.

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The fitting is angled towards 10 o'clock or so as it sits on the valve cover. I run a hose from it upwards and behind the intake manifold from the passenger side towards the driver's side and add a small filter on the end of the 2' or so hose.


Drilling out the OEM fill cap for the plastic fitting also removes the inner works that locate the 2 piece cap to its' threaded base, so I cross drilled the underneath of the cap to locate the two pieces of the cap where I wanted them, then ran a long pin through the entire assembly. You can see it sticking out of the bottom of the filler cap.



The hose angles uphill enough from the valve cover to the underneath of the cowl cover (base of the windshield) that any oil coming out of the filler cap should just drain back into the valve cover.


There's a small aluminum box underneath and in the center of the cowl cover, I've secured the hose in its' elevated position by clipping over the top of that box.