When I got this car a couple years ago, I adjusted the valves and did various maintenance work and got it running quite well. Then at some point after light driving about a year, it began shaking at idle.

It smooths out nicely when you come off idle. Here is what I'm thinking I should do- tell me if it makes sense.

1. Do a compression test. If all the cylinders are about the same, then I'm thinking I must have uneven injectors.

2. If the compression test shows some cylinders low, then I guess I better adjust the valves again.

Now- just to muddy the waters a bit- not too long after it began to shake at idle, it somehow lost its coolant and overheated while my son was driving it. After that event, it would overheat after about 10 minutes of driving, and I assumed a bad head gasket.

Against most people's advice on this forum, I tried a polymer based head gasket sealing compound (Titan). It seems to have worked- no overheating now, and no bubbles coming out of the radiator.

I only mention all this to assist in the forensics- like whatever caused it to start shaking also caused it to lose its coolant.

Thanks for any help

If I were to re-write your story I'd be saying => "A year ago the car overheated. I checked the radiator and found bubbles in the coolant. Against the advice of people on this forum I used a product called Titan to reseal the head gasket. This seemed to do the trick. However, after a year I've now got violent shaking at idle"


To my mind if you re-arrange the way in which you tell the story you can kind of see what is most likely the problem.


I'm actually impressed the quick fix additive has lasted this long - if at all (!) - I guess you've got head gasket problems again.

__________________
1992 W201 190E 1.8 171,000 km - Daily driver
1981 W123 300D ~ 100,000 miles / 160,000 km - project car stripped to the bone
1965 Land Rover Series 2a Station Wagon CIS recovery therapy!
1961 Volvo PV544 Bare metal rat rod-ish thing

I'm here to chat about cars and to help others - I'm not here "to always be right" like an internet warrior



Don't leave that there - I'll take it to bits!

...except, that is not what happened! The shaking started a few months BEFORE the overheating.

Timeline:
June 2016, bought car
Oct 2016, licensed car and put on the road
Late 2017 or early 2018 car began shaking at idle
June 2018, car overheated
August 2018, did gasket sealer
only short test drives since

After the overheating incident, I decided to try the head gasket sealer, since I didn't have much to lose. I've not driven the car hardly at all since the sealer.

Sorry about getting that wrong.


I think the point is that you had a head gasket failure and it was "fixed" by magic goo. Doing a compression test as you suggest could (re-)highlight this problem again but to my mind it seems that you already know what is wrong.


I think it is time to remove the head and see what damage has been caused. I don't think you're going to get much further by adding additives and adjusting valves this time. I'm sorry to bring you bad news...

__________________
1992 W201 190E 1.8 171,000 km - Daily driver
1981 W123 300D ~ 100,000 miles / 160,000 km - project car stripped to the bone
1965 Land Rover Series 2a Station Wagon CIS recovery therapy!
1961 Volvo PV544 Bare metal rat rod-ish thing

I'm here to chat about cars and to help others - I'm not here "to always be right" like an internet warrior



Don't leave that there - I'll take it to bits!

Actually, no, I don't know what is wrong. Are you proposing that the head gasket failed on its own, which caused the loping/shaking at idle, and then that precipitated the coolant loss and overheating? That would make some sense. The car has 200k on btw.

The gasket sealant is irrelevant to the symptom I'm trying to diagnose- the shaking, since it was applied long after the shaking began.

In any event, a compression test should reveal something.

When I bought my '82 240D the car looked pristine but it only idled on three cylinders ~ using the fast idle cable made it O.K., when I adjusted the valves the #1 exhaust valve would only get about .010" clearance and it still had a very strong soft miss @ idle, eventually I replaced the #1 cylinder's injector and it idled and ran fine for several more years, every 5,000 miles or so the #1 cylinder's exhaust valve would close up to zero lash and I'd open it as far as it'd go, never reaching anywhere near .014", in due time it got to .002" lash cold and the idle miss became bad, causing a large rhythmic 'THUMP' like a giant pounding the bottom of the car, this stopped the *instant* it went off idle and eventually even a proper set of four matched rebuilt injectors made no difference and the lash, cold or hot was at zero, I took the engine apart and along with myriad other worn out things, the #1 cylinder's exhaust valve was tulipped .

So, no harm in #1 adjusting those damn valves, why no one ever does it until the car's close to dead I'll never understand .

Then take all four injectors to a competent Diesel service shop and stand there and watch whilst they pop test all four (it takes less than 5 minutes no any excuse means they're dishonest) and unless all four are perfect, replace them .

This might well get you a few more years and tens of thousands of service .

Low compression is bad yes but, it will run passably well with anything over 250# compression if you're just looking for cheap transportation .

BT, DT, drove it across America , the Continental Divide (serious hills, that) and so on sans any troubles apart from going slowly all the way there and back so don't let the check book crowd make you give up just yet .

__________________
-Nate
1982 240D 408,XXX miles
Ignorance is the mother of suspicion and fear is the father

I did then what I knew how to do ~ now that I know better I do better

May be I'm reading your first post all wrong but it sounds to me like you had bubbles in the radiator and a failed head gasket.


Head gaskets might suddenly fail but they might be something that fails slowly.

__________________
1992 W201 190E 1.8 171,000 km - Daily driver
1981 W123 300D ~ 100,000 miles / 160,000 km - project car stripped to the bone
1965 Land Rover Series 2a Station Wagon CIS recovery therapy!
1961 Volvo PV544 Bare metal rat rod-ish thing

I'm here to chat about cars and to help others - I'm not here "to always be right" like an internet warrior



Don't leave that there - I'll take it to bits!

If I read your OP correctly you haven't adjusted your valves since acquiring the car "a couple of years ago".

I believe the FSM requires an adjustment every 15000 miles. I would try that first since it is essentially free and easy.

The odometer is not working right (gear slipping on shaft), but I'd estimate maybe 1000-2000 miles since I first got the car on the road. Still, the valves are easy enough to check, I may as well.

I'm right now trying to decide on a diesel compression tester that is not crap and I can afford.

I bought and use the Harbor Freight cheapo one, it's fine not like you're going to need it a bunch of times .

I'm sure you can find one lightly used on KIDJI, craigslist or the like , I find lots of good tools in pawn shops .

__________________
-Nate
1982 240D 408,XXX miles
Ignorance is the mother of suspicion and fear is the father

I did then what I knew how to do ~ now that I know better I do better

If you are going down the route of a compression test try to get an adapter to fit to the glow plug hole(s)


Take out all of the glow plugs rather than the injectors and save yourself the cost of new heat shields that are fit only once items.


It is unlikely the cheapest compression tester kits come with the correct fitting for the glow plugs but most leak down tester kits do...

__________________
1992 W201 190E 1.8 171,000 km - Daily driver
1981 W123 300D ~ 100,000 miles / 160,000 km - project car stripped to the bone
1965 Land Rover Series 2a Station Wagon CIS recovery therapy!
1961 Volvo PV544 Bare metal rat rod-ish thing

I'm here to chat about cars and to help others - I'm not here "to always be right" like an internet warrior



Don't leave that there - I'll take it to bits!

The el-cheapo Harbor Freight kit comes with both the injector adapter and the glow plug adapter for the pencil-style glow plugs. Shell out the $20 or so it costs and find out what the compression situation is. Is it a cheap and nasty kit? Sure. Are you a mechanic in a garage that's gonna use it every day for a living or are you just trying to diagnose a potential problem once? If the latter, don't shell out huge bucks for a basic tool you're gonna use once. You're more interested in the balance between cylinders, the precision of the peak pressure recorded isn't nearly as important.

__________________
Current stable:
1995 E320 149K (Nancy)
1983 500SL 120K (SLoL)

Black Sheep:
1985 524TD 167K (TotalDumpster™)

Gone but not forgotten:
1986 300SDL (RIP)
1991 350SD
1991 560SEL
1990 560SEL
1986 500SEL Euro (Rusted to nothing at 47K!)

Check valve clearances. Then loosen one injector line at a time. Just to establish if you have a dead cylinder at idle. Violent shaking has got to be something substantial.

What is KIDJI??

The compression test will tell a tale.

__________________
[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.