Since I had a new heated windscreen fitted my '99 3.2 has a tickover issue.
When idling the revs drop and catch up constantly. So when standing the transmission engages /disengages and the car starts shaking. When driving there are no problems.
Definitely occured after taking the car to the shop. The window guys swear they just replaced the window with nothing happening.
Would be grateful if someone has a guess.

 

If it's heated, then it must have an electrical connection, maybe a pinched wire? or rear view mirror connector? causing short circuit? try a hard reset first by disconnecting the battery, and touch negative lead briefly to positive, and re connect.

 

Thanks for the reply, I'll try it.
Also, I think I have to check cables, connectors and tubes for nicks. Any ideas for prime candidates?

 

Did the car come with the heated glass? They pull a lot of amps and require a high output alternator -- if added ... it can stress the alternator.

 

It came with the heated windscreen.

 

Got it -- I can't see what they could have done. If a primary wire was crimped -- would think the fuse would pop.

I added the heated screen to one of my old MB's -- the original alternator could not keep up and the drag slowed the engine. That's way I asked .. not sure what the amp's of the 3.2. We did not get that engine in the USA.

 

Just did the hard reset. It did not help. I now fear that the chain jumped on the left bank and started to get the valve cover off.

 

It does not sound like a timing issue to me, at least not from the symptoms you described.
However, taking off the covers for a check on timing and the tensioners is never a bad idea.

Check for oil in the spark-plug holes, and change the seals if needed (most likely if never done before).

 

Agreed. Does not sound like timing based on your original post.

This sounds more like electrical or vacuum to me.

Do you have the CEL on?

 

The sparkplug holes are clean. The cover is not off yet. The dipsrick was holding me up and it was getting dark. I had no codes on the dash qnd my cheapo obd reader was inconclusive to me. Decided to take the cover off as I thought to hear a diesel-like valve or chain noise. I has not found an damage to cables /hoses, the breather hole was not clogged. Main symptom still was the srong rev pulse in idle.

 

Thinking bit more.
To me, it sounds more air or fuel related, which can be caused by electrics such as a disconnection / bad connection during the installation of the window.

Did you check your MAF sensor functioning, as well as its connector?
A bad MAF, a bad connection, or a disconnected one, can cause up till the exact symptoms you described in your first post (although if I remember well, a full disconnection sets off the engine light).

Checking the connector is 10 seconds work, mine does a much better job if installed with some dielectric grease for good connectivity.

The MAF functioning itself can be checked with an OBD reader and running engine, although a failure might be too much of coincidence in your case.

Perhaps a start?

 

When they switched out the glass --- they had the hood open?

The intake from the air cleaner gets old and brittle -- check to make sure no one pushed /leaned on it while working on the car. common for them to crack

 

Well it's the coincidence, unfortunately: I just had the cover off and the shoe of the tensioner has gone. The chain was running on the metal core-part and has jumped one tooth, if I am correct.
Is there a way to correct the timing, when putting the new tensioner in?

 

What I mean is, can it be done without the special tools?

 

I have seen various posts on here, using zip ties to hold the chain to sprocket.

 

Well, you are a lucky man to catch it, more severe than it sounded to me.
Did you find the missing shoe?

Not sure on your mileage, but considering you have been very lucky on the secondary ones (that is if it only slipped one tooth, and you did not damage any valves), please consider the state of the primary ones as well.
The tensioners might still be doing their job, but the long chain-guides tend to fracture and break.

I remember using the zip-tie method that it is tight, but with the tensioner fully removed, I think there is sufficient space to reverse the chain, maybe by lifting the camshaft partly out.
Be sure you have the chain and the chain-wheel marked before you do so as a reference where you have to go.
4 hands will make it much easier.

However, there is one, and possible catastrophic problem if you do so; using the zip-tie method, it is absolutely necessary to have the outlet cam rotated to just that specific spot where non of the valves are suppressed.
This to prevent any stress during installation.
Those camshaft are very light, hollow, and there are several members who found out the hard way.

In your case, it is impossible to find and keep that 'sweet spot', as your exhaust cam will rotate a teeth back, creating just what you don't want.

Your call .

 

Just found a small particle of the shoe sticking in the vicinity. My guess of the one notch jump of the chain is based on the positions of the flat alignment markings as seen on the pictures. I don't know if the valves are ok.
I would now try to pull the tensioner without having to lift the camshaft. Then if there is enough leeway to lift the chain off the sprocket, rotate the camshaft back into alignment. Then ziptie chain to sprocket and rotate engine to TDC. Then lift camshaft to put in new tensioner.
Please commend if viable

 

The car has done 180000 km. The timing has been off about 100km.

 

You will need to be sure on the position of the flats by rotating the engine until they are on top. They should both be flat.
It is hard to see on the picture due to the perspective, but I do agree they are likely not aligned.

I remember I had a bit more clearance on the left tensioner, so you might be lucky. I guess it is just try and see if it works.

Remember that the cam needs to be without pressing any valves, which is, as far as I remember, not TDC, but some 1/8 of a turn further.
It is a bit hard to find, but it is definitely there.

 

Just managed to get the broken left bank tensioner replaced with the camshaft setting tool or crossbar. I also was able to get the timing right again.
On the right bank , however, I couldn't get the tensioner out with the crossbar in place. Is there a way to get the tensioner retracted?