1985 Cad Seville shift problem

[omston]

My seville 325-4l shifts hard from park to reverse and from neutral to drive also when i shift to neutral the rpm's increase and fluctuates between 800 and 1000 for some reason. It has new trans mounts and the motor mounts appear to be good. Any ideas or suggestions Im new here so id like to say hello to everyone.

[TJ Hopland]

Welcome.

You mean its difficult to pull the shift lever?   Or you mean its a very harsh clunk when it engages?

How long have you had this car?   How often does / has it got driven the last few years?

I assume this is the 4.1 gas engine, not the 5.7 diesel?

[omston]

Its a 4.1 its a clunk its not hard to pull though. It shifts fine once i'm running though. It was sitting for 12 years with other problems. I replaced the tcc solenoid and 4th gear and downshifting work  fine . Its just the clunk going in to drive and the rpm increase in neutral have to wait until it idles back down to shift to drive. Ive put about 1500 miles since i got it running again.

[omston]

 It was my dads car i never got to drive it new or near new so i don't know how it shifted then.

[omston]

It has 96000 original miles on it. I changed the fluid and filter a couple times the level when hot is in the middle of the hash marked section.

[omston]

When its in park the idle is smooth and steady it only ocilates in neutral?

[TJ Hopland]

1500 miles should be enough to get things as good as they are going to get on their own.

How many miles with the fresh transmission fluid?   I'm not a real expert on transmissions but there may be an issue there.

Were the issues that caused it to get parked mechanical issues with the car?  If so what sort of issues?   Just looking for clues as to what may be causing your idle issue?

[936CD69]

The idle seems excessively high, and you mention it fluxuates. These engines had 2 common problems, first is a worn binding shaft in the throttle body, second is a defective nose switch in the idle speed control motor. You should get no up/down play in the throttle  shaft went lifting gently up down on the arm where the cable connect. If you have play you'll need to get the throttle shaft bushing replaced or replace the throttle body itself. Isc motor can be replaced as well, it won't necessarily set a diagnostic code when it fails.

Also check the adjustment of the TV cable to the transmission, a misadjusted cable can result in incorrect transmission line pressure causing the harsh shift

HTH

Craig

[omston]

Thanks for the help.

[omston]

936 you were right the throttle shaft bushing has a lot of play.

[James Landi]

Have experienced the identical issue.  The idle control solenoid pulses in response to the computer control module... it's a very busy part, made with a worm gear and a tiny electric motor and a make/break switch on the front. As stated in the above thread, the plastic gear may be worn, and the original grease is cooked.  Suggest that you CAREFULLY remove the electrical plug to it, after the car is warmed up and at a low idle speed... at that point you'll notice no strain on the tranny when you shift. take it for a ride without the idle speed controller, but keep you foot ready to hit the gas as the engine may die for lack of rpms. I believe this idle control part is still available at NAPA, and it's not difficult to replace it. You might open yours up and see if cleaning it and replacing the grease helps. 

[omston]

James you were right i took it apart cleaned and greased it the gears were still good in it. I also retorqued the throttle body i heard a whistling noise when i cracked the throttle. Now it holds steady rpm in neutral and shifts a lot smoother thanks.

[James Landi]

Terrific... I'm so pleased for you... my 1983 had 315,000 miles, and it did the same thing.. racing, at times, and clunking into drive/ reverse-- you can't imagine my level of anxiety about all those well worn moving parts taking a hit... My Idle control servo gears were badly worn... Makes sense that the service life of such parts have limits, especially considering just how much movement that tiny device has to make when the car is running and  that the grease turns to grit after three decades.

[omston]

Hi you got 315000 on a 4.1 original engine? Did you have any head gasket problems? The internet has me afraid to drive mine normaly i drive it like its an egg afraid it will break it has 96000 original.

[James Landi]

I bought my 83 4100 in 1993 with 58k miles on it... and I never experienced an engine failure (until the end... which is a rather long story..)  I did purchase a 1985 convert. with a little of 100k, thinking that perhaps some folks just complain a lot, because by the time a bought the '85, I was well over 200k on the '83...  the '85 ran for a while but then it did developed a intake manifold leak.   I took it to Cadillac ($800) and thereafter, was religious about dropping in the leak pills (DONT USE STOP LEAK ONLY GM), renewed the coolant, etc.  Then it developed "the death rattle" at 136k... well, ok, I purchased a used 4100 from Action Auto Wrecker, Long Island, NY for $800... that one lasts for 50K--- develops a head gasket leak-- go to rebuild it, and the crankshaft thrust bearing is shot.  Meanwhile the 83 is still going strong with the same engine.  Because the convertible is unusual, I spring for an Olds conversion (265ci).  I simply have no idea why my 83 ran as well and as long as it did.  I had to change cat-converters, and some of the usually stuff.. but right up until the end, it ran like a champ.  YOu might bring this topic up else where.

[TJ Hopland]

Interesting story there James.   You went with the 260 Olds?  The 265 I think was a Pontiac.  Interesting choice or was that just the best deal for an engine?  You would have thought a 350 being much more common would have been a better deal.   The 260 was not much of an engine, like many of the downsized engines it was a lot of weight for not a lot of power and not very efficient due to the small bore requiring tiny valves.   At least they were fairly reliable. 

I had an 83 Fleetwood Coupe that I bought with around 90k on it.  Drove it another 100 with no issues.  Got a friend with an 84 Deville pushing 200k on an original motor.   Guess its like the Johnny Cash song about getting a car built on Wednesday.  If you got a Monday, Tue, Thurs, or Fri you were in trouble you got a dud. 

[omston]

Yeah i guess its just the luck of the draw and fate.

[James Landi]

I put the 260 Cid Olds in because it was in "grandma's" cream puff, low mileage '73 Cutlass.  With the two barrel carburetor and the 4100 distributor (yes, it dropped right in... can you believe it??), it has about enough power to pull the heavy convertible around with about the same mpg as the 4100. The engine weight only becomes obvious if you go in to a turn a little too fast... we had to do some re-engineering for exhaust, shift, and accelerator... all of the big parts fit.  Regarding my experiences with the 4100, as mentioned above my '83 was still running well, but it would cut out after a half hour of drive time.  I needed to bring it on a 600 mile trip--we were re-locating... no mechanic could figure out why it would simply cut out, so rather than going through a bunch of money, I gave it to a friend who sold it to someone for parts.  Was a sad day after having driven it all those miles, through many of my life's journeys. It burned a quart of oil every 1500 miles.. truly impressive.

[bcroe]

You are saying, a 4100 HEI will fit an Olds small block (and therefore also big block)?  If
some of us had known that, we'd have been using it to take advantage of the cam sensor. 

I think the lightened 260/350/403s came out in 1977.  Bruce Roe

[TJ Hopland]

I didn't think the 260 came out till 75 or 76.  Wasn't the 73 Cutlass a full size car?  Got downsized to mid size in 78?

Interesting about the distributor.   I remember the 4100 having a pretty short distributor or am I thinking of the transverse version?  Was that one different perhaps?   So you used the 4100's EFI system?

It should not have been hard to put an Olds in an E body, lots of em came with Olds motors throughout the 79-85 run.