Timing Chain, and Injection Pump

[ggspeed]

How long should it take to check these two things out and see if they need repairs etc...

Time not including the repairs, just the inspection, ad diagnostic....

Thanks

[Biodiesel300TD]

Inspecting the chain itself only take a minute or two once the valve cover is off. You'll want to check the chain stretch which will take maybe 30 minutes. So maybe an hour to remove the valve cover and check and inspect the timing and the chain.

A can't speak for the time frame for the pump. You can check the timing of the pump. But if the cam timing you checked from above is way off the IP timing will also be way off. As fro check in to see if the pump is actually working properly you'd have to take it to a Bosch Injection Service place. But these IPs are pretty hardy and don't usually go bad, but it's not unheard of.

[ggspeed]

If My Timing Chain had issues what would they be? and how would i feel it when using the car?

If my IP had issues what would that be and how would i feel that while driving the car?

[mplafleur]

As for inspecting the timing chain.

With the valve cover off, rotate the crank and look carefully at all three links between each pin. Look for a break or an elongation of the hole at the end of each link.

I removed a chain from an engine yesterday that from a mild inspection looked ok, but on close inspection I found one section that had two broken links and the third was starting to stretch and was already elongated. This chain was about to break.

Here is a picture. You can make out the broken section (the opening is pointing upward) I am trying to seperate it soI could remove it from the block.

[Diesel911]

Originally Posted by mplafleur

As for inspecting the timing chain.

With the valve cover off, rotate the crank and look carefully at all three links between each pin. Look for a break or an elongation of the hole at the end of each link.

I removed a chain from an engine yesterday that from a mild inspection looked ok, but on close inspection I found one section that had two broken links and the third was starting to stretch and was already elongated. This chain was about to break.

Here is a picture. You can make out the broken section (the opening is pointing upward) I am trying to seperate it soI could remove it from the block.

Scary!
What were the symptoms if any that caused you to take a look? Also if you checked the chain stretch before what was the stretch?

[winmutt]

Measuring Cam Timing is not an absolute measurement of Timing Chain stretch.

[Diesel911]

Originally Posted by ggspeed

If My Timing Chain had issues what would they be? and how would i feel it when using the car?

If my IP had issues what would that be and how would i feel that while driving the car?

A stretched Timing Chain has an effect on the Camshaft/Valve timing and the Fuel Injection Pump timing. Causing both to be timed Late/Retarded. General symptoms are lack of power and rough running; but that depends on how much stretch there is.
However, these symptoms can also be caused by other things.
Also other parts of the Timing Chain what I will call a system like the Timing Chain Tensioner, the Timing Chain Guide rails and wear on the IP Timer bearings will also have an effect.
Fuel Injection pump problems often show up as loss of power or rough running engine. Again however, the Fuel Injection Pump is also part of a system and the above problems can be caused by and usually are caused by other parts.
Loss of power can be caused by restricted fuel supply such as dirty fuel filter, air leaking into the suction side of the fuel system, and a restriction in the fuel supply hoses. Also a restricted Air Filter can cause loss of power.
Rough running Engine can be caused by the Fuel Injectors and air in the fuel system as well as other issues with the engine (like a burnt valve).

Checking the Fuel Injection Pump Timing (another area where the Loss Of Power problem can come up) is more than a 1 hour job if you have not done it before.
Sorry I cannot be more specific.

[ggspeed]

What does the car do when the timing chain has issues?
Symptoms for a timing chain going bad?

What happens when your injection pump doesnt work properly?

[zeke]

@Diesel911

I am trying to find the source of my poor fuel economy, and will be checking timing chain stretch and IP timing this month.
It's not valves, brakes, or leaks....which leads me to these possibilities
BUT, I have none of the symptoms you describe.

VERY smooth ride (with the exception of a but of a lurch if I rapidly apply or release the throttle)
NO smoke

Just poor mileage (18-20 mpg in a 4-sp 240D)

I don't believe the timing chain was replaced by the PO, and it has >250k on it.

SO, would you expect that I have significant stretch that need to correct with a Woodruff key if my only symptom is low mpg?

(Of course if I have stretch, my IP timing is likely off, but the same question applies to IP timing)

[Diesel911]

Here is a quick way to check the Camshaft Timing. Also, it is assumed that at the factory the Camshaft Timing was aligned to top dead center when the engine was built. A deviation from top dead center can indicate Timing Chain Stretch.

In the pic below the left half of this split pic shows the Camshaft Gear aligned to the Camshaft Bearing Tower. The right half of the pic shows the timing marks on my Crankshaft Damper. It is hard to see but I am showing 2 degrees past top dead center; indicating that my Camshaft Timing is 2 degrees late/retarded and it is considered that this is due to Timing Chain Stretch and wear on the timing chain gears and ect.

It also means that my Fuel Injection Pump timing is also late/retarded (unless someone has retimed the Pump since the Engine was built).

[ggspeed]

My deal is my 300SDL was slow, i cleaned out the overboost and it came back however an old benz mechanic in my area i have seeked help from before wants to check the timing chain and IP because i am still a little slower then usual.... I don't really wanna shell out mass amounts of coin, so i'm inquiring as to what i need to do.

Will it damage my car if i leave it?

Its not that slow should i just take it for what it is?

[Diesel911]

Originally Posted by zeke

@Diesel911

I am trying to find the source of my poor fuel economy, and will be checking timing chain stretch and IP timing this month.
It's not valves, brakes, or leaks....which leads me to these possibilities
BUT, I have none of the symptoms you describe.

VERY smooth ride (with the exception of a but of a lurch if I rapidly apply or release the throttle)
NO smoke

Just poor mileage (18-20 mpg in a 4-sp 240D)

I don't believe the timing chain was replaced by the PO, and it has >250k on it.

SO, would you expect that I have significant stretch that need to correct with a Woodruff key if my only symptom is low mpg?

(Of course if I have stretch, my IP timing is likely off, but the same question applies to IP timing)

It is hard to give a specific answer as everything on the Engine needs to be working within spec to get good mileage.

I would think that good compression, good Fuel Injectors and IP timing would go to the top of the list as having the most effect on the fuel burning. Since the Timing Chain Stretch effects the IP timing that would be something to check. (Even if you put an offset Woodruff key to correct the Camshaft Timing; after that you should still re-time the IP.)

After that what I will call the Engine breathing; getting air in and the exhaust out. Filters, Turbo in good order if you have one and unrestricted exhaust system.

Cooling system working within spec would be next.

I have been assuming you are using Diesel Fuel and also you are not running the A/C a lot of the time.

[ggspeed]

Yes I'm using diesel fuel....

[mplafleur]

Originally Posted by Diesel911

Scary!
What were the symptoms if any that caused you to take a look? Also if you checked the chain stretch before what was the stretch?

If I recall, the PO's son ran the car out of oil. (This was my car before being his)

My son bought it from him with an extra engine and parts for rebuilding. Upon removing the old engine and tearing it down for parts, I found the timing chain problem.

You should see the melted #1 main bearing!

[Diesel911]

Originally Posted by ggspeed

My deal is my 300SDL was slow, i cleaned out the overboost and it came back however an old benz mechanic in my area i have seeked help from before wants to check the timing chain and IP because i am still a little slower then usual.... I don't really wanna shell out mass amounts of coin, so i'm inquiring as to what i need to do.

Will it damage my car if i leave it?

Its not that slow should i just take it for what it is?

Unfortunately unless you are doing the labor yourself it can be expensive to have someone trouble shoot for you.
The IP timing can be a pain to do if you do not have experience and on the older cars with a gasket instead of an O-ring you may create a leak when you rotate the IP to reset the timing.
As stated before removing the valve cover to check the Camshaft Timing (which effects the IP timing since the is driven by the same chain) is not so hard to do.
If it turns out the Camshaft Timing is off 4 degrees or more (at least on my year and model there are no offset keys for less than 4 degrees of stretch) there are those offset Woodruff Keys to restore the timing and the IP timing should be brought back close also.
Since the Valve Cover is already off and everything is lined up nicely already if you had to change the key it is a matter of pulling the Camshaft Gear off and exchanging the keys (read some Threads on how it is done).