Poor Gearchange & mistiming (petrol 2.0ltr)

[seab1scuit]

Hi i had the misfortune to have an engine go on me! The timing belt knocked a hole in the rocker cover! 160,000 miles & well serviced? I got a replacement engine & fitted that, (supposedly 42,000 miles). Seemed to run ok, then on a 100 mile run when i stopped at a garage the timing had gone and engine was misfiring, really bad shudders. Switched off and 15 mins later it was ok, same happened on the return leg. Mercedes fault said Air mass sensor, so i fitted a new one. Now whenever i go uphill, the steeper the worse affected, (or try to give the car a bit stick- to overtake)the gear wont change, or somtimes after excessive revs (sounds excessive to me, 4 - 4.5000 revs)reached. After that i know my timing has gone and I have to pull over switch off engine then restart, problem solved! Any ideas?
I still have the coil pack from old engine, i will be exchanging them today! If anyone has any ideas in the meantime please let me know. I have a friend at mercedes so i can get MB computer on for diagnostics nytime.

 

[television]

Wher did you buy the MAF ????

Unplug it and try the car without, if it drives as normal then you have the answer

 

[seab1scuit]

MAF ??? is that mass air filter? mass air sensor! I was quoted £399. at MD. Autosave £69, but as hes a m8 he gave me link to ebay - £36 inc del. he says he buys of the guy all the time. he builds rally cars in his spare time! btw.
my idea of swapping coil packs did not make much difference, if anything its worse! will remove amf and report back! Just unplug it?

 

[jberks]

Sounds more like 'safe mode' than any actual timing issue.
MAS is a fair assesment though there have been lots of problems with cheap web replacements. Try Malcolms suggestion first and if it helps, I'd still avoid the internet and go to a Bosch dealer who should be able to supply something appropriate for a lot less that the MB dealer. £399 is crazy - my last one (proper MB supplied) was only £250 and I overpaid for that. I suspect the £399 included something else too.
When mine went, it took the O2 sensor with it so you may also have a secondary problem.

 

[television]

Correct Jberks the EBay ones are no good. £140 max from Bosch service centers

 

[seab1scuit]

Unplugged ams and car would start but no way would it run/drive, it is a bosch part! or very good imitation! what next to try? going on merc computer at 1pm

 

[seab1scuit]

diconnected amf,(this time engine nice & hot) and took for spin up local brae, after 300 yds it went into safe mode & slowed to such a crawl it would have stalled had i not stopped. (I had kept foot on the gas whereas before i would slacken off due to high revs and no sign of gear change) ignition off, ignition on, back to normal. this time drove normal then floored it near top 300-500 yds got it to mistime but NOT SAFEMODE, kept running and attached computer, misfiring cylinders 1 & 4. M8 says his boss had similiar prob once when it was diagnosed as HT lead/leads, which was breaking down under load! Am swapping over HT leads tomorrw, if ny thoughts please share with me. Thanking you so much for your help much appreciated having someone to speak too.

 

[seab1scuit]

sorted

Changed over the ht leads from my old engine and hey presto, everything now working fine! Thanks anyways, thread now closed!