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´95 Eldo engine oscilation ?


FSchuett

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Now,

If the engine is on and the car are not rolling, the engine run with 800 UPM very nice...

If I press the accelerator pedal the engine run very nice...

If I drive without power (downhill or before I stop without pressing the accelerator pedal) the engine oscilate from 2000 UPM to 1900 UPM (for example).

I think I feel a little restless in the car because it is the same if the ac compressor is going on. You know !

Is that normal ?

What is it ?

If I press the accelerator pedal the car goes very good.

With best wishes from germany

Frank

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Kger and I were talking, and it seems that your throttle body may be hanging up. It sounds like you are saying that its slowing down to slowly and idling too fast. Like its hard to hold it back.... Are we correct? If so, you should clean your throttle body plates and throat of any dirt or carbon buildup, especially the edges of the plates and where they contact the throat. Are you getting any codes, typically when this happens you will get a code or message. Try cleaning the throttle body, disconnect the battery to cold boot the system and restart.. let us know how this turns out... Mike

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Hi Scotty,

I don´t have any error codes.

What do you mean with "Like its hard to hold it back" ?

Is it easy to clean the trottle body plates ?

My old "service manual" is from an ´92 Eldorado and I have the ´95 Eldo,

please tell me where these part is !

Thank you very much.

Frank

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Hi Scotty,

I don´t have any error codes.

What do you mean with "Like its hard to hold it back" ?

Is it easy to clean the trottle body plates ?

My old "service manual" is from an ´92 Eldorado and I have the ´95 Eldo,

please tell me where these part is !

Thank you very much.

Frank

Frank, its easy to clean, use GM top engine cleaner, or Oxygen sensor safe carb cleaner, and use a toothbrush and clean the throttle plate and throttle body throat, dont forget the back of the plate, here is a photo of the throttle body (see circle on lower picture).. You can get in there with a rag also soaked with the cleaner.. There is a black collar that is held in place by 3 or 4 screws attached to the throttle body that you will need to remove to get full clearance to the throat, don't loose the o-ring between the collar and throttle body.. Don't forget to disconnect the battery when you are done so that the system does a re-learn procedure..otherwise it could get worse

When I say hard to hold back, I mean, it sounds like your car is surging, like it is doing 1900 RPM when it should be doing 900 RPM (sorry for not converting that to metric).. UPM? I hope this helps, Mike

post-3-1107450527_thumb.jpg

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Frank, I re-read your message. Initially I thought that your car was surging. I may have misunderstood your message. This is what I understand:

1) If the engine is on and the car are not rolling, the engine run with 800 UPM very nice. I believe you mean that idling in park the UPM is 800, 800 RPM in drive is perfect. Very nice I agree :)

2) If I press the accelerator pedal the engine run very nice. I believe you are staying that power is good, and there is no hesitation, and yes I know what very nice means in this case, awesome :P So the engine performs well..

3) If I drive without power (downhill or before I stop without pressing the accelerator pedal) the engine oscilate from 2000 UPM to 1900 UPM (for example). This was hard to translate for me, ok if you drive without power, I think you are meaning coasting, you say, downhill or coming to a stop, the engine UPM/RPM fluctuates from 2000 to 1900. You say "it is the same if the ac compressor is going on". I believe that you are feeling a surging or a cycling UPM/RPM in the 2000 UPM range and its the feeling that you get when the AC Compressor cycles on and off.

It is normal to feel the compressor cycling and even though its winter it will cycle, so its possible that you are indeed feeling the AC compressor. If this is a NEW feeling, you might want to have your AC system checked, too much refrigerant in the system can cause the high initial compressor engagement shock that you may feel. Of course if you have not had the AC charged recently that's unlikely. Also check the AC Compressor HUB bearing. If the AC hub bearing is bad the hub can momentarily bind on engagement causing you to feel it more pronounced.

4) If I press the accelerator pedal the car goes very good. Ahh yes that happens for me also! :)

I hope this helps. It won't hurt to clean the TB like I described above, she will run smooth as SILK! Very Nice!

I hope "she will run smooth as SILK" translates into German well! :D Mike

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Frank, I re-read your message. Initially I thought that your car was surging. I may have misunderstood your message. This is what I understand:

1) If the engine is on and the car are not rolling, the engine run with 800 UPM very nice. I believe you mean that idling in park the UPM is 800, I don't know what UPM 800 is, does anyone know what UPM equates to as RPM? If 800 UPM equates to +650 RPM that's perfect. Very nice I feel means the engine is smooth, nice...

2) If I press the accelerator pedal the engine run very nice. I believe you are staying that power is good, and there is no hesitation, and yes I know what very nice means in this case, awesome So the engine performs well..

3) If I drive without power (downhill or before I stop without pressing the accelerator pedal) the engine oscilate from 2000 UPM to 1900 UPM (for example). This was hard to translate for me, ok if you drive without power, I think you are meaning coasting, you say, downhill or coming to a stop, the engine UPM/RPM fluctuates from 2000 to 1900. You say "it is the same if the ac compressor is going on". I believe that you are feeling a surging or a cycling RMP in the 2000 UPM range and its the feeling that you get when the AC Compressor cycles on and off.

It is normal to feel the compressor cycling and even though its winter it will cycle, so its possible that you are indeed feeling the AC compressor. If this is a NEW feeling, you might want to have your AC system checked, too much refrigerant in the system can cause the high initial compressor engagement shock that you feel. Of course if you have not had the AC charged recently its unlikely. Also check the AC Compressor HUB bearing. If the AC hub bearing is bad the hub can momentarily bind on engagement causing you to feel it more pronounced.

4) If I press the accelerator pedal the car goes very good. Ahh yes that happens for me also!

I hope this helps, by the way, it won't hurt to clean the TB like I described above, she will become smooth as SILK! I hope "she will become smooth as SILK" translates into German well! Mike

Mike,

:D I believe 1 UPM =1 RPM (definitely has nothing to do with UPS :P ) It's

800 RPM because perhaps the engine did not warm up completely. So, the idle is fine.

NOW... Frank, what is the engine "oscillation"? Do you mean shaking or something while around 2000 RPM? Are you sure that's the engine what shakes? How about your brakes, rotors etc.?

The saddest thing in life is wasted talent

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Frank,  800 RPM in drive is perfect.

Frank, that should read, 800 RPM in PARK/NEUTRAL is perfect.

800 UPM in DRIVE is a little high assuming that UPM and RPM are the same, you should be about 650 RPM in DRIVE.

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Hello Scotty, hello adallak,

ohhhh, excuse me...

I hope you can understand my english writing but it is long ago since I went to school :lol:

Now, I think if I press the "econ" button at the AC the AC compressor is off

and if I press the "auto" button the AC compressor is going on and run !

And my problem is in the "auto" and "econ" modus...

If the AC compressor is in the "econ" modius off, is is a another problem with my Eldo, because I think I feel the AC compressor.

Engine on = AC off (I think - econ-modus) - car drive downhill - without pressing the accelerator pedal = the engine fluctuates in the range from 100 to 150 RPM

excuse me: UPM (Umdrehungen pro Minute) is RPM

Frank

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Sounds like you have surging (Kger it looks like you were right right off the bat!):

Check this post by bbobynski

Sounds like several cases of sticking EGR valves..... It is pretty simple to just remove the valve, clean the pintle shaft up inside the passage in the cast base of the valve and reinstall it. The carbon deposits on the pintle shaft will cause the valve to start to hang in the seal on the base of the valve. Just clean it up. When you do this do NOT let solvent run down the shaft into the can of the valve. It will eat the insulation off the wire windings in the can of the valve and ruin it. Just hold the valve right side up when using solvent to keep it from running down the shaft into the can.

What mechanic would tell you that an improperly operating EGR will not affect the engine operation....?????......LOL LOL He is wrong. If the valve is sticking or hanging closed it will cause detonation/spark knock and cause driveability issues due to the fuel injection system being offset lean due to the lack of the EGR. The leaness would manifest itself with sags off idle and surging and roughness while cruising. If it is sticking open it will cause sags, hesitations, surging and roughness while cruising and also cause a rough idle and stalling among other things.

Bbobynski responded to this thread

http://caddyinfo.ipbhost.com/index.php?sho...4108&hl=surging

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Hello Scotty,

My old "service manual" is from an ´92 Eldorado and I have the ´95 Eldo,

please tell me where these part is !

how can I clean the EGR valve ?

Must I uninstall these valve ?

Thank you very much for your help.

With best wishes from good old germany

Frank

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Hello Scotty,

My old "service manual" is from an ´92 Eldorado and I have the ´95 Eldo,

please tell me where these part is !

how can I clean the EGR valve ?

Must I uninstall these valve ?

Thank you very much for your help.

With best wishes from good old germany

Frank

Frank, I need to go to a meeting this morning, I will try to give you a photo and cleaning details later, Mike

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Frank, you say you have a 95, this company is having a sale on service manuals while they last, I think they were cheap ($35.00 US). Check it out if you are interested, Mike

http://www.helminc.com/helm/homepage.asp?r=

here is info from their site:

Take advantage of this special offer now through February 28, 2005, to update your past model Service Information library.

All 1995 and prior model year GM Service Manuals in stock (excluding Corvette and Print to Order manuals) are now available at the low price of $30.00 each.

In addition, all 1995 and prior model year GM Owner Manuals in stock (excluding Corvette and Print to Order manuals) are now available at the low price of $10.00 each.

Remember, this sale is only for manuals currently available in stock at Helm

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Hello Scotty,

thank you for the adress...

but the shipping cost to germany is $ 158.00 :(

I think it´s to expensive a service manual for $ 188.00 !

Now, do you have the part number for the EGR valve gasket ?

Because in your cleaning information I must replace the gasket.

Thank you

Frank

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Hi Frank,

As long as you are careful not to tear or rip the gasket while removing the EGR canister it is reuseable. Start the car and let it idle for 60 seconds and then shut the car off. The EGR canister will be slightly warm to the touch and should come off easily without harming the gasket. My gasket is the original one that came with the car. I have replaced the EGR canister once and removed it three times for cleaning.

-kg

"Burns" rubber

" I've never considered myself to be all that conservative, but it seems the more liberal some people get the more conservative I become. "

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Hello Scotty,

thank you for the adress...

but the shipping cost to germany is $ 158.00  :(

I think it´s to expensive a service manual for $ 188.00 !

Now, do you have the part number for the EGR valve gasket ?

Because in your cleaning information I must replace the gasket.

Thank you

Frank

Frank, that sounds outrageous for shipping, if you want I will check shipping for me to ship it too you. We can have them ship it to me and I can ship it to you..if you would like....we don't need OVERNIGHT, even if it takes 2 weeks, so what..let me know if you want to pursue that idea of me shipping it to you, the next time I go to the post office I will check shipping, what major city are you near?

I just bought an EGR gasket for my 96, it was $6.00, I will look at the part number for you later, its not a GM gasket however. Kger is right, if it separates easily and doesn't rip you should be OK reusing it. Is it hard to find parts for your Caddy in Germany? Mike

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Hi Scotty,

I´ve sent you an eMail...

Now, I forgot that my Eldo problem is not at every time it comes casually an most at warm engine.

If you think it´s the EGR valve I want to clean these part tomorrow

if the weather is good ;)

Gruß Frank

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Frank, I got your email, listen I would have an EGR gasket standing by if I were you, I just pulled my EGR out and the gasket stuck to both surfaces and it definately needs replacement, if you dont have a new one get it before you pull your EGR. Note you will need to lift your fuel rail to get at the EGR, luckily they replaced my fuel rail last week so it was easy to lift. My EGR was sticking closed and binding, with a bunch of round wire brushes I cleaned it really nice.. Note I used a Hoppes 22 cal rifle cleaning round steel brush to clean the seat through the second hole... as you would say....its very nice now! :lol: Here is a photo of how it looks now, its nice and shiny! Mike

If you can't get a gasket for a long time, go ahead and do it, but you may have leaking, I could send you one with the manual if you want.. I am looking into the Paypal account...

With best wishes from good old america :)

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