FAQ: Automatic Leveling Control (ALC) Concerns

Yesterday, I installed the replacement air lines, bypassing the pump with an air fill fitting. Works great! Rear of car seems about right at 50 PSI.

that part is 6.00 at oriellys

so are you going to remove th old air pump and lines since they dont work?
how often do you have to add air?

I left the air pump installed, but disconnected and removed the old lines. The air fill kit includes new lines, so I just ran them using the factory clips. There's more than enough line to locate the fitting wherever you want. I mounted mine under the rear passenger side of the car, near the muffler.

I ran with 50 psi for a week, then removed some things from the trunk and found it a little high, so let out some air - to 40psi. It's been holding for 2 weeks, no need to add air at all it seems. Maybe I'll check it in a month or two.

I really like the pump not coming on all the time, but I would eventually like to have the option to pump up the rear to 90 psi for racing.

dang, i havent pumped mine past 60 or 70, and that was due to towing.

Aaron...when you are ready to fix it., holler. I've been through all the tests.

The compressor on my 96' seems to run more than it should. If I was to look for leaks in the lines is there a common spot/problem area to look for?

I'd first suspect leaking from the shocks themselves, if they are old. Or at the ends of the lines. My shocks were REALLY crappy, looked original, and my comp had also started running a lot more than usual. Replaced with Monroe MaxAir shocks, no more problem.

I forgot to mention that I just recently replaced the shocks with Monroe's.

Probably one of the fittings (O-rings) that connect to each shock. See mention of leakage here:

https://rivperformance.editboard.com/suspension-handling-f6/write-up-rear-shocks-t1223-15.htm#15036

Well my first question is..........

I noticed when I'm on the highway and I get to around 50 mph acceleration stops and I guess u can say levels out and when I get to 60 mph I accelerate normally again? I know for a fact this is not normal. I was thinking my intake manifold is going bad or a gasket maybe? Can anyone confirm this?

And for my 2nd question is.........

When I get done driving around and I'm in park and the car is off....... I notice a humming noise from under my car and it lasts for a long time I'll say around 5 to 10 mins......I kno our cars have like a leveling system (I'm not sure what its called) for our shocks. Can anyone confirm what this problem is? Is my shocks going bad? that humming noise is bothering me......

HELP PLEASE!!!!!!!!!!!!!!!!!!!!1111111111111

Probably means either your rear shocks are leaking or the lines feeding them are.

oh ok......so if there leaking.....I'll have to get new shocks and or struts or is there a easy fix to this?

and are shocks and struts expensive?

and thanks for the reply........

¤DoughBoy¤ wrote:

Well my first question is..........

I noticed when I'm on the highway and I get to around 50 mph acceleration stops and I guess u can say levels out and when I get to 60 mph I accelerate normally again? I know for a fact this is not normal. I was thinking my intake manifold is going bad or a gasket maybe? Can anyone confirm this?

And for my 2nd question is.........

When I get done driving around and I'm in park and the car is off....... I notice a humming noise from under my car and it lasts for a long time I'll say around 5 to 10 mins......I kno our cars have like a leveling system (I'm not sure what its called) for our shocks. Can anyone confirm what this problem is? Is my shocks going bad? that humming noise is bothering me......

HELP PLEASE!!!!!!!!!!!!!!!!!!!!1111111111111

When it gets to 50mph and stops accelerating...
What is the Tach doing. It sounds like perhaps the trans. is slipping. Hard to say with the description. Elaborate a little.
Try driving in third gear for a while instead of overdrive and see if that helps to diagnose the problem.

Bert



Bert

http://www.1aauto.com/1A/shocks_struts/Buick/Riviera/1ASTS00004/395779

¤DoughBoy¤ wrote:

oh ok......so if there leaking.....I'll have to get new shocks and or struts or is there a easy fix to this?

and are shocks and struts expensive?

and thanks for the reply........

https://rivperformance.editboard.com/suspension-handling-f6/write-up-rear-shocks-t1223-15.htm#15036

Bert

Bert...

I never really looked at the tach while driving.....but I'll try to describe whats going on a little better.....

When I'm on the highway and as soon as I hit 50 mph it feels like its struggling to get pass 50 mph..it feels sluggish and as soon as I hit 60 mph it accelerates and drives normally?

At first I thought it was my transmission.....but like I said it drives perfect, just when I hit 50 mph it starts to get sluggish and then soon as I hit 60 mph its driving normal again.....

¤DoughBoy¤ wrote:

Bert...

I never really looked at the tach while driving.....but I'll try to describe whats going on a little better.....

When I'm on the highway and as soon as I hit 50 mph it feels like its struggling to get pass 50 mph..it feels sluggish and as soon as I hit 60 mph it accelerates and drives normally?

At first I thought it was my transmission.....but like I said it drives perfect, just when I hit 50 mph it starts to get sluggish and then soon as I hit 60 mph its driving normal again.....

Try it in third gear(dont go above 75mph in third) and see if you have the same symptons.
Also watch the Tach when it is acting up, if it is the transmission you will notice the RPM's increasing without the speed increasing...

Bert

ibmoses wrote:

¤DoughBoy¤ wrote:

Bert...

I never really looked at the tach while driving.....but I'll try to describe whats going on a little better.....

When I'm on the highway and as soon as I hit 50 mph it feels like its struggling to get pass 50 mph..it feels sluggish and as soon as I hit 60 mph it accelerates and drives normally?

At first I thought it was my transmission.....but like I said it drives perfect, just when I hit 50 mph it starts to get sluggish and then soon as I hit 60 mph its driving normal again.....

Try it in third gear(dont go above 75mph in third) and see if you have the same symptons.
Also watch the Tach when it is acting up, if it is the transmission you will notice the RPM's increasing without the speed increasing...

Bert

ok.....will do.................I'm gonna be leavin the house soon so I will try it out and I'll post back in here later to let u know!

if it is the tranmission, I will have to get it rebuilted?

¤DoughBoy¤ wrote:

http://www.1aauto.com/1A/shocks_struts/Buick/Riviera/1ASTS00004/395779

You probably dont need to replace the struts, they are on the front and are unrelated to the symptoms you are describing.

The noise from the rear of the car when it is parked is probably the air pump.
It is probably running because you have a leak in one or both of the rear shocks(they are air shocks). Or if you are parking on a hill the car may just be leveling itself. read this linkhttps://rivperformance.editboard.com/suspension-handling-f6/write-up-rear-shocks-t1223-15.htm#15036
and it will help to diagnose further.
Also, jack the car up and put it on some jack stands and get under there and look it over, it might be easy to fix...

Bert

OMG.....thanks for breaking it down for me Bert........appreciate it, u've been real helpful.

I found some monroes online for cheap and I'm going to get them when I get paid. bout that time to change them anyway.

do u have aim by any chance?

The Monroe rear air shocks are inexpensive and easy to install, a very good choice. Did mine last summer. My compressor had started running a lot more often than usual, and an inspection found my rear shocks were really in tough shape, looked like they could be original, at 115k miles.

On the first question... 50ish would be around the time your TC (torque converter lock up) will lock up unless you are diving hard. When the TC engages any ignition related issues are very visible. With slight increases in rpm they are less noticable. When was your last tune up?

I'd agree the noise is related to your ELC (electronic leveling control) system. The questions to ask are, is it the shocks, air lines or the compressor? All three can be the cause, the two biggest causes are struts and compressor. The lines are usually tucked away well enough that they don't rupture.

I use a small vac/low pressure gauge to test the pump by unhooking it and hooking the gauge up. Barely let the compressor run and watch the gauge (only 10psi max) if it dips soon and fast, then the problem is the compressor. If you hear a hissing from the area of the shocks...those would be the culprit (you can check further with soapy water).

BillBoost37 wrote:

......If you hear a hissing from the area of the shocks...those would be the culprit (you can check further with soapy water).

Although he won't necessarily hear hissing at the shocks, even if they are bad. My shocks were crap, but you couldn't hear any air escaping. Do the soapy water test for sure before replacing a compressor, it's damn expensive. In fact, I'd just replace the shocks if they looked like this:

Hey, how'd you get a picture of my old air shocks?!