A few weeks ago I posted a thread regarding my daughter's 1989 300TE with the stalling problem. My old mechanic kept throwing parts at it. Still, he couldn't get the problem fixed.

He is now off my list of "approved" mechanics.

I took it to my "new" mechanic. (Actually, he is an older Hungarian man who has been fixing Benzes since way back when).

After many hit and misses the new mechanic finally found the problem.

Drum rol please..........

A bad OVP.

Now, you may wonder why he did not look at the OVP first thing?

Well, the OVP had been changed a couple of years ago. When I took the car to my new mechanic I made copies of all past service records. So the new mechanic knew that the OVP was of recent vintage--and that is why he di not look at it first.

Apparently, however, the OVP went bad. and it was causing the intermittent stalling situation.

After trying out everything else the new mechanic, on a lark, put in a new OVP. And voila! that appears to have solved the stalling problem. I have driven the car for 5 days now and it has not stalled once. Let's hope this WAS the problem.

The best part of it is that although he had the car for a couple of week, he charged me only one hour's labor. The old mechanic kept charging me parts and labor for fixes that did not work. I am going to see him with a request for my money back--or else I see him in court.

Now for a couple of questions.

What would make a fairly new OVP to fail? The mechanic seems to think it was just a defective factory unit. The OVP is made in Hungary same country as my mechanic !!! Has any one out here encountered problems with defective Hungarian OVP relays?

Secod question. The old OVP rattles. When I shake it, it rattles like a baby's rattle. It sounds as if there things "loose" inside. Is this normal?

I would appreciate any and all answers to the above questions.

Thanks.

__________________
Current Benzes

1989 300TE "Alice"
1990 300CE "Sam Spade"
1991 300CE "Beowulf" RIP (06.1991 - 10.10.2007)
1998 E320 "Orson"
2002 C320 Wagon "Molly Fox"

Res non semper sunt quae esse videntur

My Gallery

Not in this weather!

I have an intermittent rough idle + occasional stall problem on my '92 300 CE-24 cab that I've been told many times is probably the OVP relay, but as it was replaced only 2 years ago I kept ignoring the advice.... til last week that is:

Read an article in a MBZ Club magazine here in the UK that described how to test the relay. It states:

"Test 1: Connect pin 30 to a +ve 12v supply and pin 31 to the -ve. Under this condition the only output should be on pin 30a.

Test 2: Now connect pin 15 to the +ve and both relays should operate with supply voltage appearing on both pin 87E and 87L".

When I did these test on my current relay, Test 1 was fine but Test 2 gave no reading on 87E or 87L, which I took to indicate that the relay was dead. I therefore ordered a new one which I got at the weekend and tested today. I was amazed though to get identical results - i.e. +ve on 15 and -ve on 31 still gave no reading off either 87E or 87L!!

Does anyone know if this test is valid and I'm doing it correctly, or is it simply that both the current and the new relay are duff and by some coincidence failing in an identical way? Also are there any other tests that can be done on the relay to test its integrity?

Note, both relays are #201 540 37 45 (9 pin, 2 red fuses and made in Hungary).

Regards,
Neil

Realise now the error in my testing: for Test 2, when you put the +ve to pin 15 this should be in addition to leaving a +ve feed to 30 (and -ve still on 31). Will repeat the tests on the old and new relays tonight.....

Congradulations on a job well done, now your car is really in tip top shape since you replaced all those parts in the long process! Thats a good thing for the car, but a bad thing for the wallet!

I have a question for you though, was your ABS light on during all these problems, my car has low idle problems and the such, many people say to replace the OVP, but my ABS light is not on, which people say is on if your OVP is bad....

Please tell me if your ABS light was on..... thanks!

I know this will sound rather comical, but the thing with the country of manufacture I think is actually mentioned in the DTB relating to failed OVP's. Not to be prejudiced, I do think it is Hungarian OVPs which are the bad ones, the "good" one I want to say are Austrian? or is it Belgium? I'd be safer trying to find the DTB, I don't think I have it though, maybe someone else does.

In regards to the ABS light and so forth, as anyone knows who has had an OVP in their hands, there are several terminals on the bottom, it would definitely be possible to have a contact fail which for example will cause the engine to stall, but not cause an ABS light. LOTS of time you do get multiple problems (stalling and ABS light, etc) but not as a strict rule.

Gilly

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Excellent response, now I know that a bad OVP does not nessessaryily trigger the ABS light. Thank you Gilly!

If all this pans out you should post it in this old thread where Cap'n Carageous searched for the solution you may have found.
Help!! Need OVP plug schematic!
-there are others who searched but don't know if they looked this hard-

__________________
-Marty

1986 300E 220,000 miles+ transmission impossible
(Now waiting under a bridge in order to become one)

Reading your M103 duty cycle:
http://www.peachparts.com/shopforum/831799-post13.html
http://www.peachparts.com/shopforum/831807-post14.html

The ABS light would occassionally come up during operation. I did not think about putting 2 and 2.

Now for the bad news. The car stalled twice today. Replacing the OVP has helped, but the engine is still cutting out when the car coasts to a stop. I have tried shifting the car from D to "3" while coasting (thus artificially raising the RPMs) and the engine does not cut out.

Tomorrow I am taking the car to Enrique at Mr. MB Motors. I spoke with him today and he is aware of the 300E stalling issue. Hopefully he will be able to fix it.

This whole situation is so aggravating because other than the stalling issue, the car runs soooooooooooo well. At 187k miles it really runs and feels like a newer car. My daughter really likes her 300TE, but if the stalling is not fixed.... we may have to reconsider our options.

I'll keep everyone posted.

__________________
Current Benzes

1989 300TE "Alice"
1990 300CE "Sam Spade"
1991 300CE "Beowulf" RIP (06.1991 - 10.10.2007)
1998 E320 "Orson"
2002 C320 Wagon "Molly Fox"

Res non semper sunt quae esse videntur

My Gallery

Not in this weather!

Trust me. Enrique can fix it.

I had a very persistent failure of the upshift delay valve for a several year duration. It would cause a the check engine light to illuminate, and would always trigger a code 26.

Two Mercedes independent shops and the Mercedes dealer in Covina (Penske Mercedes) threw parts at it, until every conceivable part related to this upshift delay function was replaced. But the damn fault code was still triggering, and the car wasn't delaying the shift from 2nd to 3rd when cold.

I dropped the car off at Enrique's shop, and after a week of troubleshooting, he was able to determine that the neutral safety switch had a short in it, which somehow, in a circuitous way, would not allow the upshift delay valve to work.

In the end, I'm not even sure if he charged me any labor for the diagnosis. All I know is that the final bill was low.

__________________
Paul S.

2001 E430, Bourdeaux Red, Oyster interior.
79,200 miles.

1973 280SE 4.5, 170,000 miles. 568 Signal Red, Black MB Tex. "The Red Baron".

BENZ-LGB, please let us know what Mr. Enrique says. I have a friend that has had this same problem for almost 3 years and have spent thousands of dollars to get it fixed. Same exact symptoms to a T - same year car, same mileage, same symptoms....... Thanks.

Thousands of dollars????

I hope not...as much as my daughter loves her car, I'd sell it if it took thatmuch $$$$$ to get it fixed right.

Paul and everyone else, I'll keep you posted

__________________
Current Benzes

1989 300TE "Alice"
1990 300CE "Sam Spade"
1991 300CE "Beowulf" RIP (06.1991 - 10.10.2007)
1998 E320 "Orson"
2002 C320 Wagon "Molly Fox"

Res non semper sunt quae esse videntur

My Gallery

Not in this weather!

Yes. Thousands. I have seen the repair bills. (I didn't say they were particularly smart.) That car has had enough new parts that have been thrown at it to make 2 additional 300TEs.

They also have a '96 S320 that they have spent as much or more on various items.

Same situation - car was given to daughter to drive. She is in college. I have some reservations about her driving the car anyway (as if it were mine!). Several months ago she got it hung up on a big metal pole (still don't know how she did it as the pole is over 3 feet tall) on the right rear. Cost a couple more thou. to get it repaired from that.
The dealer is the one they have been taking it to - they have thrown parts at that car from the day they bought it - brand new.

Anyway - I sure would like to know what you find out....

At some point you reach the point of diminishing returns. Our 300TE is a fine car that, except for the recent stalling issue, has always given good service. Still, there is no point in throwing good money after bad money.

I'll keep everyone posted on the results of Enrique's "intervention."

Yesterday I took Alice (my daughter's name for the 300TE) to Enrique. Nice shop, clean,organized, almost like going to the doctor's office. Everything that everyone here has previously posted about Enrique's shop appears to be true.

Now, if he can diagnose and cure the problem, I may have to erect a statute to the man and yank his passport so he can't ever leave the U.S.!!!

Stay tuned..............

__________________
Current Benzes

1989 300TE "Alice"
1990 300CE "Sam Spade"
1991 300CE "Beowulf" RIP (06.1991 - 10.10.2007)
1998 E320 "Orson"
2002 C320 Wagon "Molly Fox"

Res non semper sunt quae esse videntur

My Gallery

Not in this weather!

A264172,

Finally did the test correctly as follows, on both my current and the brand new OVP:

"Test 1: Connect pin 30 to a +ve 12v supply and pin 31 to the -ve. Under this condition the only output should be on pin 30a.

Test 2: In addition, now connect pin 15 to the +ve and both relays should operate with supply voltage now also appearing on both pin 87E and 87L (so all pins 'live')".

Both my OVPs passed with flying colours (note, there is an audible 'click' as power is added to pin 15).

My understanding is this is a fairly basic test: one up from checking the fuses are intact; that it doesn't rattle when you shake it; and that there's no cr@p around the pin connections.

If it fails this test you are pretty sure the OVP needs replacing, if it passes it though, there is still the possibility of an intermittent fault caused by something like a weak solder joint.....

Will post this test info on the thread link you gave in-case it's of use to someone else.

Thanks for that,
I have a good, a bad, and an ugly OVP sitting around and in use (the ugly having been replaced by an indy and put back by me when his replacement failed).
I will have to play with them, using your test when I get a chance.
Nice work.

__________________
-Marty

1986 300E 220,000 miles+ transmission impossible
(Now waiting under a bridge in order to become one)

Reading your M103 duty cycle:
http://www.peachparts.com/shopforum/831799-post13.html
http://www.peachparts.com/shopforum/831807-post14.html