R129 1991 500SL Inspection Tips

[Oliverp]

I haven't posted here in many years but have the opportunity to get back into ownership. I live in Canada now (moved from the UK).

I am going to see a 1991 500SL with relatively low miles (129k KM) - if genuine.

If I like it, I may bring a Mercedes tech with me to look at it further.
However, does anyone have any tips on what I myself could check on the first visit to decide if I should rule it out?

I was thinking
-Heater and A/C check (thinking of evaporator and heater core)
-Does the hood power up and down OK
-Rust
-Then the basics like how does it drive and how do the gear changes feel

Thanks
Oliver

[oldsinner111]

engine wiring harness too.

[Oliverp]

Thanks. Is there a way to check this visually, or are there symptoms to looks out for?
Oliver

[oldsinner111]

yes,carefully peel tape and see condition of harness

[97 SL320]

Originally Posted by Oliverp

I haven't posted here in many years but have the opportunity to get back into ownership. I live in Canada now (moved from the UK).

I am going to see a 1991 500SL with relatively low miles (129k KM) - if genuine.

If I like it, I may bring a Mercedes tech with me to look at it further.
However, does anyone have any tips on what I myself could check on the first visit to decide if I should rule it out?

I was thinking
-Heater and A/C check (thinking of evaporator and heater core)

No real way to check these. A Freon leak sniffer might pick up a whiff but even with an actual evap leak it is hard to pin down. Antifreeze smell in the car is a tip off of a possible heater core leak. These cars have a heated windshield base so coolant could leak there but I don't think it is very common.

Originally Posted by Oliverp

-Does the hood power up and down OK

If the hydraulic cylinders have not been replaced / resealed they will be leaking soon or now. There are 12 on this year of car.

Originally Posted by Oliverp

-Rust

The only time I've seen rust was on the inner door jamb and I'm guessing it was from a long ago poor quarter panel replacement.

Originally Posted by Oliverp

-Then the basics like how does it drive and how do the gear changes feel

Back the car up a steep hill with a hot transmission, these tend to lose reverse.

I don't think 91 has wiring insulation problems but can't say for sure. These do have CIS-E fuel injection that is $$$ to repair. These also have 2 fuel pumps in series to get needed pressures, one can fail and car still run but not so well.

[Oliverp]

That's great - thank you very much for your help. I will report back once I have seen the car on Saturday. I am also looking for a local MB tech who might be able to join me.

[rwd4evr]

The CIS cars still can have wiring issues. try to check where a harness is terminating into a plug in a hot area. you will see the insulation cracking and possibly falling off the wire. i would walk away if it is. The windshield washer fluid is heated by a coolant coil that can leak into the reservoir. The top hydro cylinder seals WILL go bad if they havent been replaced. it can be done at home but its very involved. FONZI did a mild restoration on one and it was a lot of little things.documentation is on b world. dash cluster issues are common. be very carefull jump starting if the battery is dead. BE absolutely sure the key is off before hooking up the cables.

[Oliverp]

So I went to see the car and I have come back a bit disappointed. At this stage I am not sure I will even come back with a mechanic.

Originally on for $14k (Canadian), now down to $8999. Advertised as amazing condition, 129k KM.

-First thing I noticed was the stong smell of gasoline when it was running. I still smell it now.
-Hard top didn't seem to be sitting properly at the back. There was quite a large gap and I could get my finger in there.
-Forward gears OK, kick down OK. Reverse gear slipping badly. I had to give it quite a bit of gas to get it to go backwards.
-Ticking coming from back of passenger side. I was wondering if this was the fuel pump or the roof assembly?
-Needs a new front bumper
-Small dings in body
-Brakes were fairly weak but OK

Good things
-No rust
-It drove quite nicely. It was still fast and steered fairly well.
-It has history

I am in two minds. Either walk away and continue the search or low ball the dealer $3k cash before he sends it to a breaker or auction.

Thanks
Oliver

[rwd4evr]

Woa!!! If you want to spend 10,000 bucks on an r129 find a post 2000 car. As much as I love the m119 the other issues don't make up for it. The m113 will be fine, it has a way better transmission and will get better mileage too. Top seals are probably toast alreadythat's why the rear is not being pulled down and latched correctly. That could be the hydraulic pump running,it's under the spare tire, that you hear clicking in the back.

[Oliverp]

Thanks, I have been looking for newer cars but I think the market up here is different (Canada vs US). Seems more expensive than in the states.
I am just wondering if low balling the dealer $3k cash is just a dumb risk, or possibly an amazing deal.
I guess the only way to tell is to get a mechanic in to look at it. I will see what the dealer is willing to accept in cash

[97 SL320]

Originally Posted by Oliverp

So I went to see the car and I have come back a bit disappointed. At this stage I am not sure I will even come back with a mechanic.

Originally on for $14k (Canadian), now down to $8999. Advertised as amazing condition, 129k KM.

The mileage doesn't matter much on a car this old, actual condition matters more. With the issues described below ( and pending issues ) this is a sub $ 1,500 USD car. If the dealer is willing to drop price from 14 to 9 and still be too high, they don't understand the market for these cars.

Originally Posted by Oliverp

-First thing I noticed was the stong smell of gasoline when it was running. I still smell it now.

-Hard top didn't seem to be sitting properly at the back. There was quite a large gap and I could get my finger in there.

This is somewhat normal, the gap isn't as tight as a door jamb.

Originally Posted by Oliverp

-Forward gears OK, kick down OK. Reverse gear slipping badly. I had to give it quite a bit of gas to get it to go backwards.

Was the engine at high revs when backing up or low revs and you had to push pedal far? If high revs, trans is slipping, if low revs, engine is down on power.

Originally Posted by Oliverp

-Ticking coming from back of passenger side. I was wondering if this was the fuel pump or the roof assembly?

Fuel pump is there. In trunk the vacuum pump for door locks is there as well.

Originally Posted by Oliverp

-Needs a new front bumper
-Small dings in body
-Brakes were fairly weak but OK

Good things
-No rust
-It drove quite nicely. It was still fast and steered fairly well.
-It has history

I am in two minds. Either walk away and continue the search or low ball the dealer $3k cash before he sends it to a breaker or auction.

Thanks
Oliver

If this car had electronic fuel injection ( 93 ? + ) it might be a good risk but with $$$ CIS-E it will be a mess to get to any decent standard. Price out a rebuilt fuel distributor , fuel pumps ( 2 ) and injectors.

Hold out for a newer car. Also don't overlook a SL320, these are less $ because many think they _need_ a V8. 97 is the optimal year due to 722.6 electronic shift trans and last year ( in North America ) for the M104 inline 6.

[Oliverp]

Thank you very much for the advice. I will skip on this one.
I haven't owned a car since 2005 (1989 W126 300SE) and I am super excited to get back into MB ownership. Trying to think sensibly is hard!
Absolutly I don't need a v8. I loved the straight six M103 - plenty enough power for me.
I will continue looking and no doubt post again soon.
Oliver

[Oliverp]

And sorry, to answer the question about reverse. I engaged reverse and basically not much happened. I tried giving a little gas and still nothing. Then I gave it a bit more and it revved quite a bit but only backed up a small amount.
Engine power seemed OK going forwards. It kicked down nicely and really got moving

[Benz Dr.]

You wouldn't happen to know a guy from Toronto named Doug who has a couple of older MB cars?

[Oliverp]

I don't think so - although I would like to meet others that own cars like this.
I moved to Toronto from England in 2011. I live right downtown.
I am actually looking for recommendations for a reputable MB tech so if Doug knows of any I would love to hear!
Thanks
Oliver