Parts Catalog Accessories Catalog How To Articles Tech Forums
Call Pelican Parts at 888-280-7799
Shopping Cart Cart | Project List | Order Status | Help




Go Back   PeachParts Mercedes-Benz Forum > Mercedes-Benz Tech Information and Support > Tech Help

Reply
 
LinkBack Thread Tools Display Modes
  #1  
Old 07-01-2005, 06:36 PM
Registered User
 
Join Date: Dec 2003
Posts: 44
Thumbs up 300E idle problems low performance, FIXED

Just finished working on my 88 300E which had developed a low and erratic idle as well as loss in performance and barely passing emissions.
After many hours of checking every possible component problem was narrowed down to two components: The OVP relay and oxygen sensor. Mind you the car already had the upgraded style OVP relay with the two fuses on. Also, the check engine light was NOT illuminating and had no trouble codes for oxygen sensor. However, since the sensor had about 100,000 miles (maybe more) I thought of changing it anyway.
Since the new oxygen sensor was close to $200, I went for the generic Bosch 13953 sensor for $43.. This turned out to be absolutely identical to the stock one and with a soldering iron some heat shrinking tube and some good soldering skills I transferred the plug from the old sensor to the new one. I took the car for a drive and there was a significant and obvious gain in performance. I usually had to drive the car with the transmission in "3" because otherwise it would not move. After the sensor change, I had to check the shifter to make sure it was in "D". Huge transformation!!

However, this did not solve the low erratic idle (about 450-500rpm), but after checking the current going to Idle control valve and realizing that it was ZERO, I suspected OVP relay. Mind you, the ABS light which sometimes is associated with broken OVP relay was not on. Anyway, after removing the OVP relay at which point the ABS light DID come on, I checked the fuses and they were fine. I put it back on and banged it a couple of times and sure enough the Idle Control Valve started working. I called the dealer to get a quote for a new OVP and they quoted me about $100. So, I took the OVP on my bench and attempted to fix it. I opened it up and discovered TWO cold and broken solders on the little pc board. I fixed all of them put it back and voila! Idles like a charm!

Just thought of posting all this to help the bros here who may have similar problems.
Reply With Quote
  #2  
Old 07-01-2005, 07:53 PM
Rahulio1989300E's Avatar
V10s & V8s FTW!
 
Join Date: Jan 2005
Posts: 1,141
Excellent work!

My car the 1989 300e, also had a similar problem,

In the mornings, when the engine was off for 8 hrs plus, I would try to start it... if it was feeling good, it ran at 400 to 500 rpm cold... usually would stall out... I would have to sit for 15 minutes while my engine warmed to 70C+ just to keep it alive... in park... putting it in gear was a different story..

I looked at my ICV first and tried cleaning it with carb cleaner, lots and lots of brown juice came out, really sick...

When is was clean, I suspected the OVP just like you, at $50+ it was pricey... but got the new one installed...

Eureka!

I got that feeling, I fixed it! I fixed it!!!

NICE WORK!
__________________
2006 BMW M5 "Heidi" @ 96,000 miles
2005 MBZ C55 AMG "Lorelai" @ 120,000 miles
1990 MBZ 500SL "Shoshanna" @ 118,000 miles
Reply With Quote
  #3  
Old 07-01-2005, 08:17 PM
Registered User
 
Join Date: Jun 2005
Posts: 20
Awesome! Thank you!!
I am currently battling similar problems on a CLK 430 (2000) with 41,000 miles. Does anyone know if there's a similar setup in my car?
BTW, what does OVP stand for?

Thanks.

Frank
Reply With Quote
  #4  
Old 07-02-2005, 12:20 AM
wbain5280's Avatar
Registered User
 
Join Date: May 2001
Location: Northern Va.
Posts: 3,386
OVP = Overvoltage Protection Relay

Its function is to blow the fuse(s) if the voltage increases too much, bad alternator regulator for instance, protecting the ECU and ABS computer. Solder joint problems are the problem.

Is Bosch becoming the new Lucas?

As for the CLK430, I don't know.
__________________
Regards

Warren

Currently 1965 220Sb, 2002 FORD Crown Vic Police Interceptor

Had 1965 220SEb, 1967 230S, 280SE 4.5, 300SE (W126), 420SEL

ENTER > = (HP RPN)

Not part of the in-crowd since 1952.
Reply With Quote
  #5  
Old 07-03-2005, 11:23 AM
jhodg5ck's Avatar
Registered User
 
Join Date: Feb 2004
Location: Atlanta, GA
Posts: 1,405
Your CLK does not have an OVP. Mb did away w/ them w/ the 140, 129 and 210 chassis cars...so now instead of blowing an OVP when voltage goes awry you take the EZL out instead. pure genius..

Jonathan
__________________
Blue Ridge Mercedes
Jonathan Hodgman
http://www.blueridgemb.com/
Enthusiast Service, Restoration & Tuning.
Follow Us on Facebook!
Located in the Atlanta area
Specializing in all pre and post merger AMG's including Hammers and DOHC M117 engines.
Mercedes Repair Atlanta
Reply With Quote
  #6  
Old 07-03-2005, 06:36 PM
Rahulio1989300E's Avatar
V10s & V8s FTW!
 
Join Date: Jan 2005
Posts: 1,141
Quote:
Originally Posted by jhodg5ck
Your CLK does not have an OVP. Mb did away w/ them w/ the 140, 129 and 210 chassis cars...so now instead of blowing an OVP when voltage goes awry you take the EZL out instead. pure genius..

Jonathan
Oh dear god...

I don't want to know the price of that EZL!!!!

And the W210's brake booster has a huge Lucas sticker on it!!!

__________________
2006 BMW M5 "Heidi" @ 96,000 miles
2005 MBZ C55 AMG "Lorelai" @ 120,000 miles
1990 MBZ 500SL "Shoshanna" @ 118,000 miles
Reply With Quote
  #7  
Old 08-10-2005, 01:38 AM
Hit Man X's Avatar
I LOVE BRUNETTES
 
Join Date: Sep 2004
Location: FUNKYTOWN
Posts: 9,085
Thumbs up

Don't mean to bring this back up, but my chum's '87 300E also has the ABS light on and idles poor.

Does this vehicle have the OVP relay like other E's and my SDL? If so, where? I didn't seem to locate it last time nosing around under the hood...
__________________
I'm not a doctor, but I'll have a look.

'85 300SD 245k
'87 300SDL 251k
'90 300SEL 326k

Six others from BMW, GM, and Ford.

Liberty will not descend to a people; a people must raise themselves to liberty.
[/IMG]
Reply With Quote
  #8  
Old 08-10-2005, 09:29 AM
Registered User
 
Join Date: Oct 2004
Location: Baton Rouge La
Posts: 2,630
Behind the battery...it's possible that you could still have a black plastic cover over the area... fuel pump and a/c relay are also back there side by side.
__________________
1989 300ce 129k
( facelifted front,updated tail lights, lowered suspension,bilstein sports, lorinser front spoiler, MOMO steering wheel, remus exhaust,stainless steel brake lines). (Gone)

1997 s320 154k (what a ride). Sold with 179k miles. Replaced with Hyundai Equus

1994 e320 Cabriolet 108k



1972 280se 4.5 153k Owned for 12 yrs, sorry I sold it


[/SIGPIC]
Reply With Quote
  #9  
Old 08-10-2005, 06:26 PM
Hit Man X's Avatar
I LOVE BRUNETTES
 
Join Date: Sep 2004
Location: FUNKYTOWN
Posts: 9,085
Thumbs up

Excellent, I'll have a look within the next day or so.
__________________
I'm not a doctor, but I'll have a look.

'85 300SD 245k
'87 300SDL 251k
'90 300SEL 326k

Six others from BMW, GM, and Ford.

Liberty will not descend to a people; a people must raise themselves to liberty.
[/IMG]
Reply With Quote
  #10  
Old 01-15-2006, 02:26 PM
Registered User
 
Join Date: Apr 2005
Posts: 51
Your a good man...

Quote:
Originally Posted by MB fan 2
Just finished working on my 88 300E which had developed a low and erratic idle as well as loss in performance and barely passing emissions.
After many hours of checking every possible component problem was narrowed down to two components: The OVP relay and oxygen sensor. Mind you the car already had the upgraded style OVP relay with the two fuses on. Also, the check engine light was NOT illuminating and had no trouble codes for oxygen sensor. However, since the sensor had about 100,000 miles (maybe more) I thought of changing it anyway.
Since the new oxygen sensor was close to $200, I went for the generic Bosch 13953 sensor for $43.. This turned out to be absolutely identical to the stock one and with a soldering iron some heat shrinking tube and some good soldering skills I transferred the plug from the old sensor to the new one. I took the car for a drive and there was a significant and obvious gain in performance. I usually had to drive the car with the transmission in "3" because otherwise it would not move. After the sensor change, I had to check the shifter to make sure it was in "D". Huge transformation!!

However, this did not solve the low erratic idle (about 450-500rpm), but after checking the current going to Idle control valve and realizing that it was ZERO, I suspected OVP relay. Mind you, the ABS light which sometimes is associated with broken OVP relay was not on. Anyway, after removing the OVP relay at which point the ABS light DID come on, I checked the fuses and they were fine. I put it back on and banged it a couple of times and sure enough the Idle Control Valve started working. I called the dealer to get a quote for a new OVP and they quoted me about $100. So, I took the OVP on my bench and attempted to fix it. I opened it up and discovered TWO cold and broken solders on the little pc board. I fixed all of them put it back and voila! Idles like a charm!

Just thought of posting all this to help the bros here who may have similar problems.
Read your thread, and your a man after my own.... Not too many guys could do this stuff!....
Reply With Quote
  #11  
Old 01-15-2006, 06:08 PM
Registered User
 
Join Date: Jul 2000
Posts: 638
MDz & Boschelectricals quality--or lack thereof

MBZ and Bosch continue to use stone-age manufacturing 'technology' in production of critical electrical/electronic components. A brand new OVP or Idle Control module from your friendly dealer will be just like the original one made 30 years ago, and probably came from the same bin of over-runs made 30 years ago. Poor solder joints are very common, 1930's vintage electrical connectors abount, and 'Edison vintage' fuses are everywhere and just as troublesome as when originally used (in1930's).

I have found a partial solution to poor connectors-- "Stabilant 22" a product repackaged by Borg-Warner as CL-5, available (usually by order) from any parts store that carries or can get a B-W product. This magic solution costs about $50 for 15 ml of a 20% solution of Stabilant-22 in iso-proply alcohol, and only a very tiny amount is needed for each contact point. It works by creeping into the minute crevices of a normal connection, sealing out water and attendant corrosion, and actually vastly improving the electrical conductivity of the connection. It is a electrically conductive polymer that acts as an insulator except in the high current micro-contact points of the connection.

this stuff will vastly improve the electrical performance of even very high quality gold-plated aero-space and computer grade connectors. Most every Xerox tech that services their high-end stuff, every IBM main-frame hardware tech, and every US military electronics tech uses the stuff now. Why it is such a hidden secret in the automotive field is a mystery. High end video and audio production shops are using it more and more, and SOME speciality 'electrical/electronics guru' automotive shops have it. It is THE ANSWER for problematic connectors--ABS connections, ETA's ALL the computer board connectors,etc. Anything that has to have a clean signal, low/no resistance, 100% reliable no noise connection should have this solution on-it.

Borg-Warner CL-85 is THE ANSWER to all those crappy connections.
Reply With Quote
  #12  
Old 01-15-2006, 06:54 PM
Registered User
 
Join Date: Jan 2006
Posts: 16
Where is the OVP relay on the 88 260E? Is it next to the fuel pump relay located behind the battery? Thx.
Reply With Quote
  #13  
Old 01-15-2006, 08:44 PM
Gilly's Avatar
Registered User
 
Join Date: Mar 2001
Location: Evansville WI
Posts: 9,616
What YOU again!? Yep, OVP is near the fuel pump relay. It's smaller than the fp relay and made of metal, has a small clear plastic cap on the top, there is a red fuse under the cap, dead giveaway that you've found it.
Gilly
Reply With Quote
  #14  
Old 01-16-2006, 01:23 PM
Registered User
 
Join Date: Jan 2006
Posts: 16
Gilly,

Yes!!! another winner. Checked the fuse on the OPV relay, but can't tell if it was bad or not. I went ahead and changed out the fuse anyway. The RPM used to be at less than 5000 now jumped up to what it supposed to be. The car used to die after the first cold start because of low idling speed. Now, it starts and keep running. Damn, I think I will quit my day time job and become a car repaiman now. OK, now tell me how to rebuild the engine, Gilly. j/k. Thanks again for the feedback.

Chris
Reply With Quote
  #15  
Old 01-16-2006, 01:35 PM
haasman's Avatar
Registered User
 
Join Date: Jun 2001
Location: San Francisco, CA
Posts: 3,097
MB fan 2

Great job! Worn and fallen engine mounts can contribute to a rough idle.

Haasman
__________________
'03 E320 Wagon-Sold
'95 E320 Wagon-Went to Ex
'93 190E 2.6-Wrecked
'91 300E-Went to Ex
'65 911 Coupe (#302580)
Reply With Quote
Reply

Bookmarks

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
'75 240 D M-style IP Theory - Help! Fisherman Diesel Discussion 29 10-06-2011 07:06 PM
300e hard warm start and stalling as rpms drop to idle MikeNJ Tech Help 1 06-13-2005 02:00 PM
High Idle - 1990 300E EasyPhil Tech Help 6 03-23-2005 03:01 PM
'91 190E 2.3 rough, low idle - fixed sbourg Tech Help 0 08-19-2001 01:17 AM
Low idle when warm Earnest Tech Help 5 08-15-2000 12:27 PM



All times are GMT -4. The time now is 04:39 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2019, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2018 Pelican Parts, LLC - Posts may be archived for display on the Peach Parts or Pelican Parts Website -    DMCA Registered Agent Contact Page