A170D Engine Change

[r44heli]

How difficult is it to remove and replace an A170 engine??
Is it a DIY project for a reasonably proficient amateur engineer, or is it a dealer/specialist job??

If its not a home job, could anyone recommend someone in the Slough area who might undertake it at a reasonable price...

Thanks.

 

[mattkh]

Hi
Just secure the car down or it will topple over when you drop the engine.
A search of this forum for 'A160' should reveal a very informative thread from down under.
What is the mileage and why are you swapping it.

 

[aliddle]

Hi,

I am not sure about the Diesel merc, but I found the A160 pretty basic. I referred to a Peter Russek "Pocket Mechanic" for all the A series petrol engines. I made a frame to hold the subframe assembly and used this to lower the engine whilst the front of the car was raised up from the rafters of my garage. Here is a picture of it:

The frame bolts onto the hole in a standard trolley jack - get a nice high one, but make sure the frame sits low on the ground. I used cable ties to strap the whole engine assembly to those adjustable/extendable arms so that, once lowered, I could push the whole thing across the garage on the trolley jack wheels.

Having the spare (old) engine is also handy to refer to whilst you are putting the whole lot back into the car.

With the manual and this to help lower the engine it was pretty basic. I didn't find a problem with the car wanting to topple over even when I didn't have it lifted up at the front - not sure what that means...?

You just look after the ECU which is the big bucks! The ECU goes with the car, not the engine so you should be ok. I found that replacement engines are cheap in Aussie as they import them from Japan where they cannot register a vehicle over 50,000kms - paid $1.9k for my complete engine which is cheaper than a set of brake disks.

The experience has given me confidence in my car and was well worth it. Just be cautious that you don't dislocate your CV joints when you drop the whole caboodle.

Be careful, the engine/gearbox is very heavy.

Good Luck and keep us informed!

 

[aliddle]

Here is a picture of the whole assembly sitting on the frame ready to push under the raised car. The back wheels are on ramps and the front needs to be raised high enough to let the engine slip underneath. I used a wooden beam under the car with either end hooked under both wheel archs and had a small 2-tonne lifter through the bonnet space to a rafter. Once the engine was under the car I lowered it all onto axle stands and took the beam out. I have tied the two suspension struts together to stop them splaying outwards and dislocating the CVs.

 

[r44heli]

The turbo failed, and I had a it replaced with a good second hand one, however, once it was fitted and running we discovered a knocking big end.
So its now an engine change....

 

[aliddle]

As a matter of interest, how did you diagnose it as a big end failure? I understand that you can pull one plug lead off at a time and the one that results in the knock going away is the one with the big end gone - it would be interesting to test this! What do you think caused the failure?

Be sure about the source of the knock whilst the engine is still able to run! Don't start stripping until you are sure.

If it is a buggered BE, you don't think it worthwhile considering replacing the bearings by taking the head and sump off? Whilst it is an option to go the whole hog and "fix it all" whilst you have it in pieces this can get very expensive (and arguably unnecessary), however just looking at the engine that I removed I would be quite confident to clean it all up and stick it back together without changing anything - including the old bearings and even the old head gasket! Whilst I am not advocating this in your case - perhaps you should just consider replacing what is broken only? What do you use the car for? Is it worth spending a lot of money on it?

 

[r44heli]

Hi,

Thanks for reply - a diesel doesn't have plug leads!!
You can hear the knocking easily when the engine runs.

Does it make sense to strip engine down, and renew big-ends??
Other damage may have occurred??

Anyone on this forum ever changed an A170 engine?

Thanx

 

[aliddle]

MMnnnh...

Yeah.... No plug leads...(duh!)

If you really want to swop the engine then get a manual and check it out:

http://www.click2add.co.uk/index.html?target=dept_64.html
http://www.electronicmanuals.co.uk/mercedes-aclass-workshop-manual-p-188.html

Like I said - if you are keen, it is dead easy.

Alan

 

[aliddle]

Just thinking....

If you are going to swop the engine out It would be a great opportunity to do a bit of experimenting before you do it. There are ways of diagnosing where a knock is likely to be coming from:

- Disconnect one lead at a time to the injectors to disable each cylinder one at a time and check the knock, so if it is a BE then it will not knock if it doesn't fire;

- Run the engine at different revs and loads and check the knock, you could video the rev counter and have the sound on whilst you are driving and give commentary on what you are hearing. A piston slap will be more prevalent at the top end of a rev under load;

- etc.... Anyone else got any bright ideas? (I'll check the web for more);

AL

 

[aliddle]

Here is a web page on diagnosing engine knocks:

http://remanufactured-engines.com/page4.htm

There must be heaps more...

 

[aliddle]

Hi R44,

What is the latest on your car? Just thinking (again) what is the background to this car? Why did it (seem to) start knocking only after you fixed the turbo?.... We are itching to find out!

 

[r44heli]

History as follows - Bought car for ex-wife, after year one paid for a full service, then told her it was down to her to look after it. 2 years later, the turbo starts whining like a jet engine, she askd me whats up with it, I check the oil and its not even on the dipstick. Asked her if it had been serviced and she said she forgot.... 1 week later the turbo goes bang around 10 miles from home, she drives it home and calls me. I buy a secondhand turbo and have it fitted, on first start the technician calls me to tell me the big ends have gone...

Latest news... obtained a good 90,000 mile engine with full service history and its being fitted today.

Anyone want an A170D engine that needs new big ends, let me know.

Thanks for your support.

 

[aliddle]

Eeesh. I guess the big ends must have gone....!

Thanks for that & good luck.

 

[r44heli]

New engine now installed and running. All is fine with the exception of the engine hunting at idle, and slight hesitance at very low throttle openings. Car has been on Merc analyser and no faults read.

Any suggestions??