OIl pressure and tapping

Ok so I know as much as my transmission needs replaced or rebuilt do to the slipping. But if I keep from pushing it, it will last for now. Lately, my Riv has been releasing exhaust I can see even when its not cold enough. Its white, but not thick. Whispy is more the word, like its barely burning excess oil. Its strange, cause the oil level never drops and it gets an oil changed every 3 months religiously. I do monthly checkups to make sure everything is copesthetic. Oil seems to be staying cleaner longer as well. It doesnt get dark like it used to a couple years ago.

I have been watching the OIl Pressure readings on the CRT Gauge screen while driving it. Its been idling rough lately so I figured Id start there. I noticed last year that the oil pressure, when idling, even keeping a steady speed, jumps around A LOT. Going from 30s to high 60s while idling and 40s to mid 70s when going at a steady speed. Last year I replaced the OIl Pressure Sensor and, all at once, the car seemed to idle better. The oil pressure gauge readings were steady. They barely jumped around at all. Everything seemed to run smoother. Now, its at it again. Could it be more then something to do with that sensor?

Ive also been getting annoyed with the valve tapping going on. It used to be that, when I would give it an oil change the tapping would quiet down, until it was getting close for its next change. Used to be the worst when idling. While acclerating the engine, it would damn near disappear. Now it just seems more prominent all around. I have a feeling there is nothing I can do to adjust the rockers to help fix that. Being its an '88, I was told that they werent adjustable.

I love my Riv to death. Most think im down right crazy for trying to tinker with it and id be better off selling it for scrap. I guess they just dont understand someone who has a true passion for working on cars. Let alone all the time and effort Ive put into this one. Its such a rare find, my Riv. People are always astounded by how loaded it is for its age. And I get the greatest feeling of accomplishment when I fix something and it makes it work better, stronger, or at all. My ultimate project would be to take out the engine and tranny and rebuild them completely. But without the resources (money, necessary tools, know how), im kinda up the creek without a paddle. So if anyone has any cost effective ideas for where to start with the above mentioned issues, please share.

I'd pull a few plugs and look at them. Then I would put a vacuum gauge on the engine and see what it was pulling fully warmed up in Park/Neutral. Your rough idle has a cause, and it is not the oil pressure. It's likely the oil pressure readings are jumping around because of the rough idle, and that CRT screen cannot react as quickly as a good gauge. Finally, if you are hearing tapping from the valves, pull the valve cover on that side and make sure it isn't a worn/broken rocker or bent push rod. look at the rocker shaft and mounting. You may see something obvious.

Well, thats a start. Not sure what a vacuum gauge is or where to get one, but ill do some research. Ive been tempted to pull the valve covers, just to see whats what. Its more then likely the rear set of cylinders.

My other fun project is so see what I can do with this computer system diagnostic. Pressing warm and off on my CRT Climate screen opens up the computers full diagnostic. I get full readings of any sensor in the engine, relays, you name it. There is overrides for lots of things. Just trying something, I overrode the IAC motor, cant remember if I lowered the setting or rose the setting but, turning my car back on, it seemed to run a smidge smoother. Oil pressure leveled out a bit better. Im wondering if I can override the injectors in conjuction with the IAC and fix the fuel/air ratio to reduce the exhaust smell. Wish I knew how indepth this system really went and how to fix it. Somehow I dont think even a buick dealer would be able to work with it or reset it to factory settings.

If you have a dead cylinder that is putting unburned gas into the catalytic converter, that will melt and clog the converter.

A vacuum gauge is an essential diagnostic tool for a mechanic. They are cheap and available ANYWHERE.

I assure you I dont have a "dead" cylinder. My computer would be freaking out and telling me. Not to mention, the car would be running like complete crap. (SideNote: Ive been in the situation when I tried E3 diamond fire plugs, They dont agree with my car.) Checking all the plugs, I dont notice anything major. They all look like normal operation plugs. The front plugs (2,4,and 6) show evidence of running a bit hot, but not by much. I think its cylinder 1's plug that has the tiniest bit of wetness around the plug threads. I check them every month and a half to make sure the clearances are good, they are running normal, and to clean them off. They havent changed for a few years. Before they ran straight up hot until I flushed my radiator and added Wetter the Water to the antifreeze.

Ill check for that vacuum gauge tonight and may get one over the weekend. Ill post results sunday at the latest. Then we can go from there. Thanks for the insight.

As for the transmission slipping, check if your brakes are dragging. If your calipers have metal pucks and have been in for some years they might well be. A hint is brake fluid dark like coffee, means it's wet and should have been flushed. What happens is either internal corrosion in the bores (not so likely) or the seals wear and the pistons cock and catch in the bores (more likely) so that it takes a while for brakes to release.

As for the wispy exhaust, if you use the car for city suburban short trip driving the condensation can collect in the muffler such that it will take a very long time to heat up enough to blow out. I would have to know temperatures and drive cycle to say more, though. You rarely get oil smoke out of cars with functioning cats because once the cat reaches light off temp (iirc takes 30 sec or so on newer ones) it burns the oil fumes coming thru and you never see them. My understanding is more than one hi mileage 3800 could use refreshed valve guides and engine seals.

Albertj

The brake fluid does get a bit darker. I have pumped a lot of fluid out before. The calipers are not much more then a year old. And I had to bleed the lines to remove any air. I didnt fully flush them though. I know my tranny is slipping. Brakes shouldnt be to blame. Although, the back calipers are a bit tight/barely touching because I had to adjust the E-brake. The tranny has an issue shifting into 2nd gear when the car is cold or jackrabbit started off a line. I have to let off the gas when it shifts to 2nd so it doesnt harshly buck the car. Thought about maybe starting with the shifter soleniod. Ive replaced the filter and fluid a couple years ago. Didnt have any metal shavings in the pan. It looked remarkably clean. Tranny fluid is a bit dark, but not too bad.

As for the exhaust, I never thought of that. But I do drive it for a couple 10 mile trips during the week nights. Dont drive it everyday either. So that makes sense. And yeah I agree. It could used newer seals and such. Its 25 years old afterall.

As for the diagnotics system. I can override the IAC motor while im in the computer, but as soon as I leave it, the system goes back to its orignal settings. So thats a bust.

Wolfmaster579 wrote:

The brake fluid does get a bit darker. I have pumped a lot of fluid out before. The calipers are not much more then a year old. And I had to bleed the lines to remove any air. I didnt fully flush them though. I know my tranny is slipping. Brakes shouldnt be to blame. Although, the back calipers are a bit tight/barely touching because I had to adjust the E-brake. The tranny has an issue shifting into 2nd gear when the car is cold or jackrabbit started off a line. I have to let off the gas when it shifts to 2nd so it doesnt harshly buck the car. Thought about maybe starting with the shifter soleniod. Ive replaced the filter and fluid a couple years ago. Didnt have any metal shavings in the pan. It looked remarkably clean. Tranny fluid is a bit dark, but not too bad.

As for the exhaust, I never thought of that. But I do drive it for a couple 10 mile trips during the week nights. Dont drive it everyday either. So that makes sense. And yeah I agree. It could used newer seals and such. Its 25 years old afterall.

As for the diagnotics system. I can override the IAC motor while im in the computer, but as soon as I leave it, the system goes back to its orignal settings. So thats a bust.

you might get an improvement in shift behavilr by disconnecting the battery and letting the PCM default to the factory settings. First be sure your radio Theftlock is not engaged, then disconnect the + cable from the battery. I have heard that you may need to ground the + cable for a while (15 min to an hour or so) to drain the backup caps but I don't really know.

Alright I got this vacuum gauge. Not strictly a vacuum gauge cause all they could find was vacuum/boost gauges, but i digress. The gauge came with everything but something to splice into a vacuum line. It says brake vacuum lines may not be the best to use because of improper readings. My Haynes manual says to connect it to the intake manifold vacuum and the picture they give as an example is of a four barrel carbuerated V8 engine. Not exactly helpful. So what would be the best place to connect it. I work better with visual aids. I can take a picture and post it, once i figure out how, if you'd be able to point out where from that.

Wolfmaster579 wrote:

Alright I got this vacuum gauge. Not strictly a vacuum gauge cause all they could find was vacuum/boost gauges, but i digress. The gauge came with everything but something to splice into a vacuum line. It says brake vacuum lines may not be the best to use because of improper readings. My Haynes manual says to connect it to the intake manifold vacuum and the picture they give as an example is of a four barrel carbuerated V8 engine. Not exactly helpful. So what would be the best place to connect it. I work better with visual aids. I can take a picture and post it, once i figure out how, if you'd be able to point out where from that.

Hopefully some others will chime in but I'm thinking the right place to connect if your riv is supercharged s the vacuum manifold that connects the boost valve etc. You should be able to trace it from a small nipple on the passenger side of the base of the lower intake manifold. If not supercharged look for vac lines in the vicinity of the PCV valve.

Other thoughts?

Any vacuum line on the intake should suffice on your car. Regarding your trans problem, you might try replacing the modulator. It controls line pressure and may be defective also causing your white smoke problem.

Only vac line in the vacinity of the PCV valve for me is the PCV valve. everything else is plug wires and electrical lines for the alternator.

Alright, new update. A couple weeks ago, I found a plastic line, under my air filter box, that came out of a rubber tube. I put it back in then not thinking anything of it. It was out again when I looked today. I followed the line back, and it ends up hooking into the manifold, right after the throttle body. I unhooked it from that point and turned on the car. It had plenty vacuum. When I slid the small tubing of the vacuum gauge in it and held the fitting tight, because it doesnt hook tightly, the gauge started giving me readings. At normal operating temperatures and at idle, it holds steady at 19 in-HG. Doesnt jump around, and according to my haynes manual its within the normal range. It reacts normally when i do the rev test too.

So now what would cause the tapping? You'd think that worn seals, valves, valve springs, or such would change the readings on the gauge accordingly.

Tapping can be caused by damaged or worn valve train parts, rocker arm push rods, etc. Take the valve cover off and have a look.

Not sure if Ill do that this weekend, but I will do that. I have to remove a bunch of stuff to get them off, and Id like to get new gaskets and such. I may just replace the rockers and pushrods just for the sake of doing so. Ultimately, Id love to take out the intake manifold, and the heads, just because that whole area needs majorly cleaned as well as get new gaskets and seals, fuel injectors, you name it. But I just dont have the time these days. Cause once I start, id want to keep going. Curse my drive to fix things.

Replaced the worn 2" rubber tube that connected that vacuum line under my air cleaner box. As well as its middle connector rubber tube and the one that is connected to the transmission control modulator. Took the Buick out for a spin.

The tapping reduced a lot during idle, just there during acceleration now. It even idles smoother. The oil pressure leveled out. Acceleration is smoother, quicker/more responsive. It feels a little stronger then before. The shift from first to second is a little smoother too. It still bucks when you push it into second, but not nearly as bad.

Amazing what a stinking vacuum line can do. Thank you Larry for the idea for the vacuum gauge. I never would of inspected all my vacuum lines as closely if I didnt. Now we'll see if my gas mileage kicks back up again. Still intend to check under the valve covers, but when I get more time.

By the time your done with the old gal,i'm sure they will all, been replaced!!