OK, the weather is nice, the year is nearly over and I need to get off my rear and do something (running 10 miles this morning wasn't enough ... ). I figure I might try cleaning the lines to the overboost protection relay and to the ALDA. I'm sure there's some soot in there. I've been reading and reading previous threads, and my one paranoia (well, OK, I have about 543 paranoias, but I'll just voice the one) is that I'm going to booger something up and make the overboost relay nonfunctional, causing my car to get too much boost and ruin everything. Is disassembling/reassembling this stuff pretty much idiot proof or should I not attack this? Anything I should check for to assure proper function upon reassembly? My plan is to take the lines out, clean them with WD40 and pipe cleaners and put them back on. Is that the whole shebang?

Oh, and should I actually try to clean up the connections/nipples on the overboost relay, intake manifold and ALDA, too? Or just the lines?

__________________
1987 300D, arctic white/palomino--314,000 miles
1978 240D 4-speed, Euro Delivery, light ivory/bamboo--370,000 miles
2005 Jeep Liberty CRD Limited, light khaki/slate--140,000 miles
2018 Chevy Cruze diesel, 6-speed manual, satin steel metallic/kalahari--19,000 miles
1982 Peugeot 505 diesel, 4-speed manual, blue/blue, 130,000 miles
1995 S320, black/parchment--34,000 miles (Dad's car)

Most of the "stuff" is usually located in the hollow bolt at the intake manifold and in the first few inches of the line that attaches to that bolt. Except in extreme cases, there is no need to clean the switchover valve itself.

OK ... so I dove right in. And created a mess. First of all, when I lightly gripped the line from the manifold to the overboost relay, it snapped! So I guess that needed to be replaced, not cleaned. No problem ... I bought some line as a safeguard. Then I couldn't get the screws out of the retaining clips on the connecting tube. Is there some secret to doing this or am I just inept? They are totally corroded solid and there's no way to get a good grip on them to get any leverage with the screw driver. I ended up having to remove the overboost relay and eventually cut off the connecting hose and clip. I do not have replacements for the clips and rubber connectors. They didn't have any in stock at the dealership, which I found out after about 20 minutes of trying to explain to the guy who works there what I needed. He looked at me like I was speaking Spanish when I mentioned things like the ALDA and overboost relay. I had to draw him a DIAGRAM. LOL.
Anyhow, now I have no line between the relay and the manifold, and I'm sure the line between the ALDA and relay is equally brittle and crudded. So, here are the questions:
1) I could only get the hose for the manifold to relay ... they did not have the hose for the ALDA to relay in stock. Can the first hose be used for both applications? As far as I can see, the only difference is a red line on the side of the latter. I have a meter of the plain line.
2) Is there a trick to getting those screws out or do I have to completely demolish all the clamps and just replace them?
3) The nipple on the manifold is very cruddy. Should I stick a pipe cleaner in there, or just squirt carb cleaner in the hole?
How do I manage to turn the simplest of things into meltdown?
Here are some photos of my huge mess. At left is dirty line and new line ... yuck. Middle shows the devil screw brackets. Right is the end of the hose off the manifold ... cruddy.

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__________________
1987 300D, arctic white/palomino--314,000 miles
1978 240D 4-speed, Euro Delivery, light ivory/bamboo--370,000 miles
2005 Jeep Liberty CRD Limited, light khaki/slate--140,000 miles
2018 Chevy Cruze diesel, 6-speed manual, satin steel metallic/kalahari--19,000 miles
1982 Peugeot 505 diesel, 4-speed manual, blue/blue, 130,000 miles
1995 S320, black/parchment--34,000 miles (Dad's car)

1) The hose is the same. The color on the outside of the hose is irrelevant. The standard hose can be used for both.

2) The trick is extreme hand strength. Sorry, but you'll need someone who can apply massive force to a phillips screwdriver while simultaneously resisting that force with his opposite hand. This usually works, but, if the clamp is truly corroded beyond recognition, it must be cut off.

3) Use a stock pipe cleaner if you have one. Carb cleaner on a plastic tube will also be fine unless the hole is really plugged solid.


Old cars do that to you. It's not related to your experience. Fasteners that have not been moved in 20 years are difficult to move.........even with a lot of force. It's part of the deal with old cars............makes them a challenge.

BTW, you can plumb it up without the clamps. The system will probably hold for a short time if the hoses fit tightly to the fittings. The overboost valve is the place to use a clamp if you have one.

Thanks a million Brian. I figure the bright side of this is at least I tried something new ... AND it wasn't a bad way to find out what bad condition those lines were in. I'll have to find a fella to help me try to loosen those screws ... I did get one off with some WD40 and a lot of effort, so they might be undoable with more strength. The bad news is, with the holiday Monday, I can't get to the dealership for replacements until Tuesday at the earliest. So I guess the Jeep will get some action. At least there is a different dealer nearby, so they may have the connectors/clamps in stock, or they might at least have a better idea of what I'm talking about. I never want to be rude, but this kid that works in the dealer close to me just has no idea.

One quick Q ... what is a "stock" pipe cleaner as opposed to just a pipe cleaner? I was just going to look for something at the hardware store.

__________________
1987 300D, arctic white/palomino--314,000 miles
1978 240D 4-speed, Euro Delivery, light ivory/bamboo--370,000 miles
2005 Jeep Liberty CRD Limited, light khaki/slate--140,000 miles
2018 Chevy Cruze diesel, 6-speed manual, satin steel metallic/kalahari--19,000 miles
1982 Peugeot 505 diesel, 4-speed manual, blue/blue, 130,000 miles
1995 S320, black/parchment--34,000 miles (Dad's car)

Join the club with the clueless dealers. I can't get parts from my brother's dealership unless I'm extra lucky. Request a "wastegate hose" and my brother brings home a "cigar hose". Yeah........they're both "hoses"................

I cannot explain why I selected the word "stock". It's clearly confusing. Maybe I was thinking "standard". Any old pipe cleaner will just be perfect............

I'll go out on a limb and speculate that "stock" translates to "ordinary." But I'll have to admit that a lifelong allergy to tobacco smoke has interfered significantly with my education on pipe cleaning techniques and equipment.

Your experience with the dealership parts "experts" is far from unique. Even more frustrating than their lack of knowledge is their unwillingness to acknowlege that, every now and then, the customer does know what he or she is talking about.

Those damned clips are a pain. I figured out the trick though. If you have a sweatshirt on, just stretch the arm of the sweatshirt over your hand and you'll be able to compress the clips without making your fingers bloody. Screwdriver never worked well for me, hands are the way to do it.

__________________
1985 CA 300D Turbo , 213K mi

Ah, I thought maybe you were just making sure I didn't use a pipe cleaner that was chipped or intercooled or something.

I had to laugh, though. By the time I got to the point where I was drawing pictures, I had a couple people waiting in line behind me so I let them go ahead of me while I sketched away. The very nice lady behind me asked me "Are you a mechanic?" I just smiled and said ... "well ... I'm trying!" She was picking up a motor mount and was concerned that maybe she had not gotten the right thing because she expected it to be bigger (she must have been picking it up for a husband or other garage or something) ... naturally the guy behind the counter couldn't really explain what a motor mount was, so I helped. It made me feel like a real genius, to look at it in a positive light. It was also kind of neat to see another woman who actually had an interest in knowing which parts do what. I don't think she was going to do the work on the car, but she had a pretty good idea of what the mount was for, and was interested enough to find out more.

Thanks for the help and the tips, guys. I'll keep you updated when I can get my hands on these bits and pieces and get poor Bodhi out of driveway lockdown.

__________________
1987 300D, arctic white/palomino--314,000 miles
1978 240D 4-speed, Euro Delivery, light ivory/bamboo--370,000 miles
2005 Jeep Liberty CRD Limited, light khaki/slate--140,000 miles
2018 Chevy Cruze diesel, 6-speed manual, satin steel metallic/kalahari--19,000 miles
1982 Peugeot 505 diesel, 4-speed manual, blue/blue, 130,000 miles
1995 S320, black/parchment--34,000 miles (Dad's car)

OK ... all systems are go again ... at least I hope so! I drove up to the far-away dealership to get my parts, and they had everything in stock ... and a REALLY nice parts dept., worth the drive. I replaced the switchover valve and both lines as well as all the rubber connectors. I cleaned the nipple on the intake and gently cleaned the tip of the nipple on the ALDA (it was pretty clear already) and also cleaned the contacts on the electrical fitting before I put it on the new switchover valve. I took it for a drive and everything seems fine ... the car feels a little livelier off the line, which would make sense, given the incredible amount of crud in the lines I took out. It also might just feel fast because I spent the morning driving my mom's big dog of a Suburban!
A couple wrap up questions:
1) What exactly does the electrical switch on the bottom of the switchover valve do?
2) What is the other line that comes out of the Y fitting on the ALDA? I did not change this line, just put it right back into the new fitting, and tried to be as careful as possible with it. It seems less brittle than the other two, and it was clean, so I figured it was OK. What does it do?
3) How do I know I did this job right? It looks good and drives well, but I don't want to pat myself on the back just yet ... close, though ... I actually got something done!

__________________
1987 300D, arctic white/palomino--314,000 miles
1978 240D 4-speed, Euro Delivery, light ivory/bamboo--370,000 miles
2005 Jeep Liberty CRD Limited, light khaki/slate--140,000 miles
2018 Chevy Cruze diesel, 6-speed manual, satin steel metallic/kalahari--19,000 miles
1982 Peugeot 505 diesel, 4-speed manual, blue/blue, 130,000 miles
1995 S320, black/parchment--34,000 miles (Dad's car)

1) The valve is an electrical solenoid. When the sensor on the manifold triggers the valve to close, the boost signal from the manifold is blocked and the ALDA line is vented to the atmosphere.

2) The second line is the boost line to the blue flying saucer on the driver's fenderwell. It serves to reduce transmission vacuum to nearly zero when the engine is under maximum boost.

3) I know that you did the job right.

Great job!
a girl willing to get grease under her nails is a VERY rare commodity, BE very choosy with guys. we are all the same... well us mechanics are anyway... keep on learning.
where on the east coast are you anyway?
John

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John HAUL AWAY, OR CRUSHED CARS!!! HELP ME keep the cars out of the crusher! A/C Thread
"as I ride with my a/c on... I have fond memories of sweaty oily saturdays and spewing R12 into the air. THANKS for all you do!

My drivers:
1987 190D 2.5Turbo
1987 560SL convertible
1987 190D 2.5-5SPEED!!!

1987 300TD
2005 Dodge Sprinter 2500 158"WB
1994GMC 2500 6.5Turbo truck... I had to put the ladder somewhere!

Ah, that sounds along the lines of what I thought. One thing I can't seem to find is the sensor on the manifold. The diagram I have looks like the switch is on the intake manifold not far from the pressure line that runs to the bottom nipple on the switchover valve. The electrical fitting that plugs into the bottom of the switch on the valve runs back and through the firewall a few inches from the switch ... where it goes from there, I can't seem to follow. So now the system makes sense to me ... I just can't seem to figure out the whereabouts of the wire. Basically, I want to make sure the wire is connected to the sensor it's supposed to be connected to on the intake.

One more thing: On the top pipe of my switchover valve, there was a small "cap." It's been on my valve the whole time, so when I replaced the valve with a new one (which did not come with a "cap"), I took the cap off the old one and put it on the new one. I'm beginning to wonder if that cap is supposed to be there, though ... how can the pressure vent out if that pipe is covered? Is it a cap designed to release the pressure at a certain rate? Here's my old switchover valve (nice and cruddy ... new one is GOLDEN!), with said top pipe uncapped. Should there be a "cap" on top of it, or not?

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__________________
1987 300D, arctic white/palomino--314,000 miles
1978 240D 4-speed, Euro Delivery, light ivory/bamboo--370,000 miles
2005 Jeep Liberty CRD Limited, light khaki/slate--140,000 miles
2018 Chevy Cruze diesel, 6-speed manual, satin steel metallic/kalahari--19,000 miles
1982 Peugeot 505 diesel, 4-speed manual, blue/blue, 130,000 miles
1995 S320, black/parchment--34,000 miles (Dad's car)

OK, I just looked in the engine compartment and noticed the sensor right above the pressure line on the manifold ... guess that's my sensor, eh? I guess the wire just goes way back behind the firewall to keep it out of the way?

__________________
1987 300D, arctic white/palomino--314,000 miles
1978 240D 4-speed, Euro Delivery, light ivory/bamboo--370,000 miles
2005 Jeep Liberty CRD Limited, light khaki/slate--140,000 miles
2018 Chevy Cruze diesel, 6-speed manual, satin steel metallic/kalahari--19,000 miles
1982 Peugeot 505 diesel, 4-speed manual, blue/blue, 130,000 miles
1995 S320, black/parchment--34,000 miles (Dad's car)

Here's what I did a few months ago to my overboost solenoid ... I was experimenting under the guidance of several really great guys on this site.

I checked all the lines, fittings, etc - found no blockages. I cleaned out the solenoid carefully. Put all together and got OK performance, but not nearly as good as when I bypass the solenoid.

I get about the same MPG as before, but the driveability is pretty awesome - no lag in boost, actually chirped my wornout tires once in a while ...

Assuming my wastegate is operating properly, will I really affect anything with this "mod?"

BTW, I have noticed nothing out of the ordinary after having lived with the mod for a couple of months.

George

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George Stephenson
1991 350 SDL (200K and she ain't bent, yet)
former 2002 E320 4Matic Wagon - good car
former 1985 300 CD - great car
former 1981 300 TD - good car
former 1972 280 SEL - not so good car
a couple of those diesel Rabbits ...40-45 mpg