1987 560 sl - PeachParts Mercedes-Benz Forum

pool boy · #1 04-01-2013, 10:13 AM

Started the 560 Sunday morning as usual. Idle a bit high. Waited a second and it increased to 2200 rpm. Also noted the SRS light was on. Both things new for this car. Are they related? Checked the vacuum line from manifold to brake booster appears o.k. except the in line check valve (?) plastic housing is degraded. Brake pedal fells normal. Instinct is to replace vacuum line. Any thoughts or suggestions greatly appreciated.

rocky raccoon · #2 04-01-2013, 08:36 PM

vacuum-intensive. Any signs of deteriorated connectors or fittings must be replaced. Where is your "economy" gauge reading? If it is not pegged to the right at idle, you have a vac leak.

TIP: On the rear of the intake manifold, approximately center between the manifold and the firewall you will find a right-angle rubber vac fitting. It is very hard to see and to access hence it is seldom inspected or replaced. Bet you it has failed and that is the source.

Please let us know what you find out.

rowdie · #3 04-01-2013, 08:59 PM

I think you meant pegged to the left.
Check the fuse on the OVP relay.

abiby · #4 04-01-2013, 09:24 PM

Quote:

Originally Posted by rowdie

I think you meant pegged to the left.
Check the fuse on the OVP relay.

Do you ever get tired of being right?

rocky raccoon · #5 04-02-2013, 06:21 AM

to see if Rowdie was still alive.

meltedpanda · #6 04-02-2013, 03:38 PM

Quote:

Originally Posted by abiby

Do you ever get tired of being right?

, I learned not to mess with him

pool boy · #7 04-02-2013, 05:16 PM

Quote:

Originally Posted by rocky raccoon

vacuum-intensive. Any signs of deteriorated connectors or fittings must be replaced. Where is your "economy" gauge reading? If it is not pegged to the right at idle, you have a vac leak.

TIP: On the rear of the intake manifold, approximately center between the manifold and the firewall you will find a right-angle rubber vac fitting. It is very hard to see and to access hence it is seldom inspected or replaced. Bet you it has failed and that is the source.

Please let us know what you find out.

Thanks a lot for the help. I did find a line loose at the front of the engine. The part is described as a "vacuum control valve - engine vacuum". It is black plastic round about two inches in diameter and located behind and slightly to the left of the distributer. There are two lines attached to the bottom and one on the top which goes down and under the distributer. There is a black rubber 90 on the end of the tube. This is the line that is not attached and I can't see where it attaches. Any clues? Also, I mis-wrote, it is the antilock light that stays on. Thanks again for the help.

rowdie · #8 04-03-2013, 08:13 AM

The high idle ABS light combination is common with an OVP failure. The fuse on top of it may or may not be bad. The relay is old and maybe just failed.
I'll try to figure out what vacuum line is in question. Are you describing L&R as looking from the front? As the saying goes pictures are worth.................
What color is the plastic vacuum line?

Thanks for the faith guys even though I am still learning along with everyone else.

Walrus · #9 04-05-2013, 04:06 PM

Quote:

Originally Posted by rowdie

...Thanks for the faith guys even though I am still learning along with everyone else.

Hell, you done fergot more'n most of us will ever know...

pool boy · #10 04-27-2013, 05:05 PM

Very sorry for the tardy reply. Crunch time for my business so just got back to the project car. Thanks so very much to Rowdie and the other guys for their help. It was the OVP relay. Got it installed and car is back to normal. And Rowdie, I tried taking pics but they will not open in Windows 8. I'll have to get one of the kids to help. But, the vac line is plugged and the car is running fine. So I don't know what that vac assembly is for. (My smart a** friend next door said it's probably the cigarette lighter.) Again thanks a heap.