Girlfriend's 240D might be going out :(
 

Car in question is a late-model '79 240D auto.

Hard to start when cold, smokes a lot, and coolant disappears out of nowhere. I'm putting my money on a head gasket failure. Wasn't really expecting this, so what should I do? the thought of pulling the head off scares me, and I don't have the proper tools/equipment to pull this job off. Worst of all, it's her daily driver; she needs it.
I have a HF compression tester that I was planning on using on it, because it's so hard (if not impossible) to start the thing up during these cold mornings. However, going through the trouble may just seem like a moot point now considering all other factors.

Try and fix it? Or sell as a parts car? :confused:

Hows your fuel delivery ?
How long since you set the valves ?
Whats the condition of your battery ?

240's are pretty easy to work on.

For a $100 or so you can get all the tools you need for DIY fixing
Harbor Freight Tools

You may be jumping the gun with this car. Based on the symptoms that you describe, a bad head gasket is not the likely problem. There are a few reasons that the car may be hard to start on a cold morning, and they can appear to indicate a serious problem when acting in combination. Smoke that is smoke, not steam, is not much of an indicator of a blown head gasket. It is amazing how much coolant can disappear if there is a very tiny leak in the radiator that goes unnoticed, more so if you have a faulty radiator cap.

Have the valves been adjusted recently? Had they been adjusted regularly prior to the last adjustment? Are the glow plugs known to be good? Have you tried cycling them a few times before trying to start?

Since you already have a compression tester, it would be a good idea to test. If you have low compression across the board, or a pair of low cylinders that might indicate a bad HG, then you will have more quality information knowing your compression numbers. You should, of course, check and adjust valve lash before you do a compression test. Testing through the glow plug holes will also force you to examine the glow plugs. You might have a bad one, and if you still have the original loop style plugs that would mean that none of your glow plugs are working. For that matter, the problem could be as simple as a bad glow plug fuse.

A pressure test of the cooling system may throw some light on the situation as well. If the system can't hold pressure and you can't find a leak, then you may very well have some seepage at the HG. The point that I'm making is that a decision to pull the head should be made only with a lot stronger evidence than is being presented. OTOH, a decision to get rid of the car may be the easiest way out if other circumstances dictate.

left coast is simply saying ...dont assume the worst. None of were born with wrenches in our hands, we all learned one bolt/nut at a time

Couple of things:

1) Adjust the valves, test the glow plugs, take a compression test.

2) Don't be afraid of the head gasket. I pulled an engine this summer after having done nothing greater than change transmission fluid in the Corolla the year before. Most of the work is just "intelligent grunt work" -- follow directions, get the right tools, and you will be fine. You can do it.

the chance of a catastrophic head gasket failure on a 616 is extreeemely low.

a friends 240d was getting impossible to start and a new set of glow plugs fixed that problem. i think yr gf's 79 still has the series plugs which makes it even more imperative to check the glow plugs first!!!

There are many possible causes for loss of coolant:
Visible radiator hoses - do an inspection. Look for signs of rust deposition from dried radiator water.
There is a tiny section of radiator hose between the front engine thermostat housing and the water pump I think. It's a regular inch or so length of hose that is hard to see unless you know where to look.
Pinholes in the radiator - look for the signs of water leaking out under pressure.

As for hard starting - glow plugs, glow plug timer, wires. Lack of air flow - check filter for blockage.

Fuel delivery as stated.

Also as suggested, don't jump to conclusions that all is lost. Check the little stuff first and rule it out.

Thanks fella
 

Thanks for all the replies, guys. I'll get on some stuff tomorrow.

I recently did a valve adjustment on her car; I tend to do them twice a year to both of our cars, if nothing else; once before winter/cold autumn, and one after winter/before the warmer weather. They hadn't changed much from the previous adjustment in May; maybe two had tightened enough that I actually had to do something.

I've been iffy on the battery; it always tests out good in battery checks at auto stores and even my own tests; I use a multimeter and a load tester from Harbor Freight (Alternator/Battery Tester) The part I'm iffy on is that besides the fact that it says Interstate on the back, there's no markings whatsoever on it. Money pending, I've been contemplating getting a new one. I've heard good things about Interstate batteries; got one in my own car and it's awesome. :D

I did replace the starter motor about 4, 5 months ago with a unit for turbo engines (spins faster I guess) to help alleviate this issue.

I'm not sure how I would check fuel delivery...I keep tabs on the fuel filters, though. Just replaced the pre-filter about a month ago and the spin-on about 2, 3 months ago. Haven't had a chance to inspect the tank screen, however. I caved a while ago and bought the 'special socket' from y'allknowwhoSource to replace mine on my car, so I have the resources/know-how.

Same deal with a radiator pressure test, checking the glow plug box/timer...elaborate how-to please? :)

The engine on this takes the later-style pencil glowplugs. Like I said, it's a late-model 79, almost 80. Mine is an early model, stamped 1978; it has the older, larger holes that I upgraded to a parallel system. However, I have little history on her car so for all I know the engine was swapped from another car. :rolleyes:
Now, I've seem some posts on here detailing glow plug testing on these pencil plugs using a multimeter to measure resistance and whatnot...I got lost. :confused: I should just take them out and test to see if they even get red-hot first?

This is the best way IMO to test them. Use a set of jumper cables and a good battery to test them, the tips on all of them should get bright red.

If your worried about a head gasket leak, however unlikely it is, buy a cheap diesel compatible leak tester. They fit in where the rad cap goes and test for combustion gasses in the cooling system.

Answer
 

Don't waste time...

Take the car to a repair shop for a cooling system pressure test.

If there is no external leak = 99.9% odds the head gasket is bad.

If you continue driving with a bad head gasket = begging for more damage or catastrophic failure.

*************

After 34 years, the head gasket is IMO an expected maintenance item.

The DIY requires few special tools.
Untitled Document


If you share your (CITY) location, a local member may be able to help you.

,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,

Home Made Special Tools, This is where members can share how they made special tools
http://www.peachparts.com/shopforum/general-information/239902-home-made-special-tools-where-members-can-share-how-they-made-special-tools.html


Cavitation
http://www.peachparts.com/shopforum/general-information/272132-cavitation.html

1980 240D CRACKED cylinder head + cavitation damage
http://www.peachparts.com/shopforum/diesel-discussion/325016-1980-240d-cracked-cylinder-head-cavitation-damage.html

1985 300TD head gasket repair
http://www.peachparts.com/shopforum/diesel-discussion/325433-1985-300td-head-gasket-repair.html

240D (616) # of cylinder head bolts? (how many of each length)
http://www.peachparts.com/shopforum/diesel-discussion/278841-240d-616-cylinder-head-bolts.html

<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<


If this is a critical vehicle that can't be down for service, I suggest you:

#1. Call me = check your PM for my number. Note: You also have E-mail.

#2. Buy a good used cylinder head
Mercede Benz W123 240D 616 Engine Head 4 Cylinder Diesel Non Turbo 616 016 14 01 | eBay

#3. Take car and spare cylinder head to a repair shop.

#4. Pick up and pay for the completed vehicle in a few days.

.

For some reason that special tools link isn't working. :confused:

My location is Marysville/Everett, WA. Anyone know of a reputable shop around this area that can/will do an old Benz? Also...roughly how much is a head gasket replacement job from a shop? :o

I did fail to mention that I am getting some leaking from underneath the IP... it looks like oil but to the touch it's way too thin to be oil. A coolant/oil mix, perhaps?

Also, check your email... :P

Try this..... http://www.peachparts.com/shopforum/washington/183891-everett-sno-co-gp-automotive.html I'm in SW Washington, about 3 hours away. If I had time off work I would give you a hand checking it, but it sounds like you have a good handle on it!

FYI
 

Here are direct links to the service - repair manuals:
FYI If you have problems accessing these documents, try using Internet Explorer..

The DIY requires few special tools.
Untitled Document

Here are direct links to the service - repair manuals:
FYI If you have problems accessing these documents, try using Internet Explorer..



Mercedes Benz (EPC) Electronic Parts Catalog
EPC-net Online

Remove all versions of JAVA on your computer using add or remove programs or programs and features in the control panel.

Go to Where can I get the latest version of Java 6?

Download the 32 BIT version of JAVA, version 38, install and retry EPC.net.

32 BIT is required for EPC.net and version 6.

Version 7 or 64bit versions are not supported at this time.

***************************************************

For those of you who are unaware, Mercedes has posted up all the service manuals for our favorite cars on their Star TekInfo website, no need to login at all.

STAR TekInfo

Click, MB Workshop Resources -> Service Manual Library CD/DVD

Here are direct links to the service - repair manuals:
FYI If you have problems accessing these documents, try using Internet Explorer..

124:
Model 124

107:
Model 107

123:
Model 123

126:
Model 126

201:
Model 201

Hope this helps!

.

I can confirm that startek does not like Firefcx, even the latest version.
Seems like IE is their 'preferred' browser for full operation.

Stab in the dark but I would say $1000-1200 for the HG.

GP test results
 

Just tested the glowplugs. Wasn't too happy with the results, heh.

Started by removing all 4 from the engine...from rear to front, numbers 4 and 3 didn't have that much carbon buildup on them, but #2 and #1 did. I thought "oh there's the problem! #1 and #2 are bum!" Well...not quite. Exactly the opposite, really.

I couldn't get to my battery charger, so I just tested them in the car off the car battery. To verify the relay worked, I took a spare large-thread plug I had laying around for my car and hooked it right up to the wire from the relay. Turn the key ...yay! Glows beautifully. So, relay works (woohoo!). To establish a ground to the plug, I just nestled it in the ground frame on the back of the engine. I then took all 4 and tested them this way. To be sure I had a good ground, I tested each three different times and re-positioned in the frame hole if they didn't glow the first time.

The results....the two caked with carbon are good. The two for the front of the engine...uh oh. Explains a bit of the hard starting, heh. :o

Also, I took pictures this time! :D Now I just have to figure out how to get them on here in a decent enough resolution...so pics to come later. The majority of them are of underneath the car, where the leaking is coming from.

Oil and water don't mix. Oil and diesel do mix. Clean the mess up and look for fuel leaks.

I second the suggestion to get the cooling system pressure tested at a reliable shop. The necessary tools will cost at least as much as having it done once, and an experienced tech is more likely to find the problem quickly.

FYI
 

Send the RAW pictures to me for posting on this thread.


.

Update!
 

Ordered and installed new Bosch glowplugs; reamed out the holes while I was at it and figured I'd do a compression test too. Got my lovely lady out to help me; she cranked the engine while I read the gauge. :D All 4 cylinders capped on about the 6th, 7th stroke at around 400 PSI, give or take a bit. Installed the new glowplugs with copper antiseize on the threads. The real test will be when she starts it tomorrow morning. The test was done with the engine warm, through the GP holes (obviously). I made sure to check each new gp before I installed them. :)

Oh, and the leaking? Fuel. From the IP where the hardline to injector #1 is. Is there a seal underneath that hex or something? :confused:

Answer
 

Loosen the compression nut, move the line slightly (it should come straight up), re-tighten lightly and keep tweaking until it does not leak.

Be careful you don't (Gorilla) over tighten the fitting.

.

Could you explain a bit more of this? I'm not entirely sure what you're referring to.

The lines that go back to the injector pump are held in place with nuts on the injector pump. Follow whunter's directions from there.

Uh...
 

Which is the compression nut...? From what I see, each section has 3 nuts; one large one where the fuel comes out and two smaller ones flanking it.

I think he means the nut connecting the hard line running from the injector to the IP to the IP. It's a 14 mm, I think.

the 240 and older diesel motors should have 17mm wrench size hard line nuts on them.

Ah
 

Gotcha.

Yup.

OM61x = 17mm nuts
OM60x = 14 mm nuts

Been a while since I played with them, I guess :).