Check engine light

[Hotwheels]

I recently picked up a '91 Olds 88 Royale from my fiance's grandmother with only 114k original miles on it. It's one of those typical little old lady cars that was driven to the bank, store, and church, and probably never saw much above 50mph. Well, it's in great shape (save for the surface rust setting in on the quarters, which I'm about to tackle) but I'm wondering what I should do to it to get it tuned up to be my daily work car.

Upon driving the car back from Wells, MN - (about 20mi. W of Albert Lea) to my place, 5 1/2 hours north, I did a WOT sprint, and promptly set off the check engine light, which has continued to be on. I was guessing it probably has some carbon buildup, and might still have the original plugs, etc. All fluids are of good color, full, and look relatively fresh. I had the local auto parts store scan the car, which came up with a code for what the sales associate said was a "cam sensor" of some sort. (He unplugged it and shut it off before I could get the exact code from him - I'm just repeating what he told me). If that was true....this thing would hardly run, right? It runs and drives wonderfully! The guy there said he couldn't reset the code for me - I would need to disconnect the battery in order to clear it. Haven't had a pre-OBD-II car, so does all of this sound right? Does this sound like a fluke, or is there something I should be checking for?

Taking it back home, it also got 23.5mpg driven moderately at 74/75mph on I-35. This seems low for a 3800 - I've taken a few others on trips and have usually gotten 27-30mpg - driven comparably, but those were with Series II cars. Do you have any ideas on how far off this seems, what I could do to help it run at peak efficiency? I'm going to go through it tomorrow with a knowledgeable mechanic buddy of mine, and planning on checking/replacing the air filter, replacing spark plugs, running Seafoam, and cleaning the TB if need be, etc. Anything else I should be doing/checking?

...Sorry for the long post, but thanks in advance for your help.

[myfirstbonnie]

Here is how to read the codes yourself: http://www.pontiacbonnevilleclub.com/fo ... =51&t=8689

Here is the list of code definitions: http://www.pontiacbonnevilleclub.com/fo ... =51&t=1624

As for resetting the CEL, you can disconnect the battery for 5 minutes or more and it clears them. Along with doing the normal tune up items (plugs, wires, PCV valve, air filter, oil and filter) be sure to clean the TB and IAC port. You can even upgrade the coils from the single pack to the newer 3 coil design.

While under the car and changing the oil, give the catalytic converter a good smack with a rubber mallet or your foot and listen for it to rattle. If it rattles, it will need replaced.

[crzydmnd72]

My money is on code 41. WOT, cam walks forward a little and knocks out cam magnet

[RJolly87]

I will have to agree, and, now it is too late, but usually some discretion is recommended before cutting loose a car that has likely never seen wot before. It is my understanding that the rings wear groves in the cylinder walls, and when the car does not see many rpm's, the grooves are rather small. When you go WOT, you now jam the rings past the end of the groves, and run the risk of damage. I haven't heard many cases of it, but feel it is worth mentioning. Gotta work it in.

Once the motor is worked in good, a seafoam treatment will probably be really good, and post beatdown from the seafoam, do a full tuneup, also replacing filters that need to be changed, and aren't even really sure on.

I did this to my Park Avenue, almost 3 years ago, and it became a whole new car. I also stuck with top tier gas, and haven't had any carbon buildup issues that I can detect, and the car still runs just about as good as it did right after the tuneup.

[Hotwheels]

Ok thanks, that is good info to know. I'm pretty sure that it is a code 41 as well. I'll have to run the procedure that was linked above to verify though. I don't drive hard at all - I baby every vehicle I own, so will this become a "non-problem" as the car gets used more - aka, eventually, will the CEL not come on?

This weekend, I changed the plugs with the recommended Autolites, cleaned the TB, MAF, and airbox, installed a new air filter, and checked over everything. I also put a full bottle of Seafoam in the 3/4 tank of gas that was in it. The oil change has like 600 miles on it or so, so I will just let that be for now. All fluids look good, including bright tranny fluid. It has a recent looking AC Delco battery, as well as a nearly new looking alternator and EGR valve. I also took the time to grind down the surface rust on the rear doglegs and quarters and repainted with the correct paint. Whew....logged about 11 hours working on that thing yesterday - mostly all bodywork. But, it's shaping up quite nicely! I'll try to post some pics soon.

The Mustang is going into winter storage later this week - I'm stalling, cause the forecast is calling for 55 degree temps till Wed But...the Olds will turn into my main vehicle starting Thurs or so. So...other than avoiding hard throttle, is there anything else I should be doing or checking to avoid any issues with the CEL issue?


P.S. - BigRed - my fiance drove a '91 Park Avenue nearly identical to yours when I first met her. It was a fully baked UT car with 236,000 miles, but drove like brand new - it was such a great car! I had a '98 Monte Carlo Z34 at the time with ~120k miles, and the Park Avenue was actually just as nice or nicer to drive, lol! Love these 3800 cars

[RJolly87]

P.S. - BigRed - my fiance drove a '91 Park Avenue nearly identical to yours when I first met her. It was a fully baked UT car with 236,000 miles, but drove like brand new - it was such a great car! I had a '98 Monte Carlo Z34 at the time with ~120k miles, and the Park Avenue was actually just as nice or nicer to drive, lol! Love these 3800 cars

Yup! BTW, Big Red is the name of the car, not me.

Don't get me wrong about the full throttle thing. By all means, start using it, but it must be a gradual process over time. Start working it out, and start stretching her legs, just don't take her for a full run at first.

[Hotwheels]

LOL....oh man...should've noticed your name! I think I've spent too much time out in the garage smelling paint fumes!

[crzydmnd72]

To properly fix it, you will need to pull the timing cover and put a new magnet in the sprocket. Its all but mandatory to put a new chain and sprockets on as well...however there is a method that involves JB weld and a steady hand thru the sensor hole. I've never been brave enough to try that, so I've just torn it down and installed new parts

[RJolly87]

Any luck pulling codes yet? Don't start throwing money at it until you know what is going on. If it is a code 41 though, it will not go away until it gets fixed.

[Hotwheels]

Yeesh. Sounds like a complicated fix. Sorry I haven't gotten a chance to pull the codes yet - I've been driving the Mustang yesterday and today, before it goes into storage tomorrow or Thursday, and have also had an online class that takes all of my time on Mon/Tues. Tomorrow, I'll pull the code after work, and we'll go from there!

One thing I did happen to notice, is that when I moved it around in the driveway today, it was running fine as I backed it out and repositioned it, but then fell flat on its face and died once putting it into drive. My buddy (a 25+ yr mechanic for the county) who helped drive it home, had it die once in Cloquet (4+ hours into the otherwise uneventful trip) unexpectedly upon stopping at a stoplight, but it started right back up. Hasn't had so much as a hiccup since, until today. Any chance this is related? I'm really hoping this isn't going to be a pain to fix :S I'll keep ya posted as to what I find tomorrow.

[crzydmnd72]

If you're comfortable with a wrench, its not a bad job at all. If you're a novice, its still not a bad job. Take a few pics and don't rush it. Toughest part is the crank sensor. There's a special tool used to set the air gap, but most folks just use feeler gauges to get it even. Last one I set was outdoors, a mist turned into a blinding rain and I still got it right, so its not terrible either.

Be careful removing the harmonic balancer, there are slotted rings in it that bend easily and one revolution will destroy the crank sensor. BTDT And be prepared to get a new HB if the rubber is rotted out.

ETA, went looking for a Techinfo but didn't find one. A Haynes or Chiltons is a great help also

[1oldman]

Shop Manual by Helms

http://www.books4cars.com

91 88 Shop Service Repair Manual by Oldsmobile for 1991 Delta Eighty Eight & Royale $39.95

Good Luck! - BC

[Hotwheels]

Well, I pulled the codes after work today, and it is code 41. The Olds is my primary car as of today (put the Stang in storage), so it'll be getting used every day. One thing I'm noticing, both yesterday and today, is that there is a slight chugging for just a second only when accelerating from a stop. If I accelerate from even a 5mph start, there is no problem. It's the same sort of feeling that you would get if you tried accelerating on ice with traction control on - a brief, pulsating cut of engine power. Would this be a part of this issue with the code 41? I just changed the plugs, etc., so I wouldn't think that would be it.

So....I'm trying to put together all of what needs to be done from the various responses - I need to change the timing chain, magnet, and sprockets, which involves removing the crank sensor and harmonic balancer?

[RJolly87]

Ours did that when it threw a code 41. You will want to confirm it in fact threw the magnet by pulling the cam sensor and looking through the hole to confirm the magnet is missing. You will need to pull the timing cover off, which means the harmonic balancer, crank sensor, water pump, etc need to come off. Once the timing cover is off, the rest is a cakewalk. While tearing down, examine parts as they come off to ensure that replacement is not needed.

Couple tips:

I seem to remember the pulley has to come off the water pump for removal. Crack those bolts loose while the drivebelt is still on.
You will need a harmonic balancer puller.
You will need to get that stupid harmonic balancer bolt broken loose. That may involve power tools <we actually broke some on ours>, bumping the starter with a breaker bar lodged on the bolt, or jamming a prybar in the teeth of the flex plate by way of the inspection cover near the starter <This way allows the most torque to be put down IMO, It took us 2 guys, a 24 inch breaker bar, and more profanity than we care to admit to break that bolt loose>

[Hotwheels]

Ok, thanks - that helps me know what I'm getting myself into. I was hoping I would be set for a while with this car, but it looks like it will be another full weekend of wrenching on it!

So, when you did yours, did you just replace the magnet, or did you replace anything else? Obviously, some of it will depend on condition as I pull it apart - aka water pump, etc. Do auto parts stores carry that magnet, or where can I find another, if it is gone? And as for the harmonic balancer puller, is that something that could be rented at an auto parts store, or will I need to purchase that somewhere else?

[myfirstbonnie]

Depending on the finances and your desires, I would do the following while it is apart:

1. The timing set witha new chain tensioner. The original tensioner was plastic and eroded quite a bit.



2. The magnet is actually called the interupter
3. The water pump, just because it is there and going to be off anyways.
4. The PCV valve due to the acess
5. The drive belt if showing any wear


Be sure to put a little sealant in the corners of the front cover where the oil pan, block and front cover all come together. The HB puller can either be rented, borrowed or purchased at any parts store, but they do not have the correct bolts in the kit. I do not remember the size and length, but I will look them up unless someone else chimes in before I do.

[Hotwheels]

Sorry to revive the thread again, but I need a couple pointers. I'm looking to possibly tackle the project this weekend, and need to buy any parts needed probably tomorrow or Friday.

These 3800's are plentiful enough, that with 4 auto parts stores in town, I'm sure if I decide I want to replace the belt, water pump, or whatever else on a whim, it should be in stock. But...the one thing I'm wondering about is this cam magnet/interrupter - will an auto parts store even know what I'm talking about, or is this something I need to call my GM dealer to order? Any recommendations on who to call and what to ask for? Aside from the obvious things that I could choose whether to replace or not (drive belt, water pump, etc.), is there anything else that is directly involved in solving the problem itself that I should purchase, besides this magnet?

[00Beast]

Parts store should know what it is. I'd replace the timing chain and the cover gasket, as well as the cam sensor and the water pump.

[Hotwheels]

Sorry to revive an old post again (!), but I thought I'd let you know how everything turned out.

Last Saturday, I was able to get the cam interrupter changed out the easy way, lol. Since the both the belt and water pump appear to have been replaced already at 114k, I figured I should see if the it could be replaced the easy way first, before tearing everything apart:

To properly fix it, you will need to pull the timing cover and put a new magnet in the sprocket. Its all but mandatory to put a new chain and sprockets on as well...however there is a method that involves JB weld and a steady hand thru the sensor hole. I've never been brave enough to try that, so I've just torn it down and installed new parts

Since the interrupter cost me $13, I figured it was a risk worth taking, and if it didn't work, I'd just take it apart the normal way, checking other parts as I go.

So....that's what I did - removed the coolant and window washer bottles, along with the battery, belt, and tensioner pulley, etc. for more access. What took FOREVER was trying to fish out the old interrupter - it was broken into a couple pieces, and was pretty difficult to fish out through the sensor hole. I used the smallest tools I could find (even a dental pick!) and a mirror, working in reverse (b/c of the mirror) trying to get it out. Wow, was that trying my patience! A friend that was helping carefully ground down the outer flanges of the new interrupter to get it to fit into the hole from the front side vs. the back side. We eventually got it back in with JB Weld, and let it set overnight. It set nice and firm, so we buttoned it all back up. After a 10-15 mile test drive Sunday afternoon, (and having disconnected the battery as well) the check engine light didn't come back on, and all of its previous symptoms disappeared! I've been driving it a week since (every day), with no such problems.

Oh, and btw.....here is the pic from my iPhone of what we found immediately after taking out the cam sensor - couldn't have lined it up better if we tried!



So....5-6 hours of work later, I'm only in it $13!

[00Beast]

Good work!!! Glad to hear you got 'er fixed!