10 valve or 20 valve

Whats the obvious way of knowing which is which on the 850 series? Does the 20 have more ooomph!!!? And finally is either type the one to avoid?

Reply to
xntrick
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The 20 Valve will say so right on the engine in big obvious lettering. Yes it's significantly more powerful, and no not really any reason to avoid either, both require careful attention to the timing belt replacement schedule.

Reply to
James Sweet

10's will say "DOHC" and 20's will say "20 valve" on the black plastic cam cover.

Also can determine which engine and number of valves from the engine code, which willbe on the cam belt cover on a white sticker:

EG

B 5 20 4 F x

5 cyl 2.0 liter 4valves/cyl naturally asp sometimes extra digit present, sometimes not

B5234T4 would be 5 cyl, 2.3liter, 4 valves, turbo. (in this case high pressure)

As general rules:

Avoid the both variants of the 2litre- especially with auto box; not really powerful enough

2.5 10v auto, again struggles abit, but capable 8 out 10 times.

2.5 10v manual entirely capable unless regularly fully loaded. Most common. Good engine, abit lazy in power delivery but a good slogger. Pulls well from

2500-5000rpm. High gearing on manuals blunts it, but effortless cruiser once upto speed. Happier at 100mph than 70.

Only thing to watch is the exhaust manifold is unique to this engine (B5252S ) and the flexi pipe occasionally begins to leak after 80-100k miles. Good 2nd hand manifolds are vvvv rare, new ones 400quid. Check carefully.

2.5 20v- carries on where the 10valver becomes uninterested- after 5000rpm. mpg only very slightly lower than the 10v. Better choice if you want an auto or tow.

2.5T best engine of the lot. Power at any revs, any gear. Deceptively fast and effortless. Mpg late 20's to early 30's. Rare. Front tyre wear a slight issue.

2.3T5. at times violently powerful. Traction control attempts to control it but usually fails. Front Tyre wear a serious issue- manuals especially savage. Can be heavy on fuel, and slightly more susceptable to poor maintanance.

With all engines- broken timing belt results in scrap engine. Not known as a belt breaker though. Belt change interval on cam belt cover. Regular fresh oil (every 5-6k miles) and fresh coolant every 24months and they'll all do

200k without problems.

Hydraulic tappets should be silent immediately from cold start. If not- walk away. Head gaskets occasionally go at over 100k- purely from lack of fresh coolant. Due to engine construction its neither quick nor cheap to change it and expect it to remain leak free done on the cheap.

Manual clutches last well- over 100k miles usually (except on t5's) but again not cheap to replace due to complexity. A cheap job usually always results in recurring problems after.

Autoboxes can pack up around 100k due to lack of specified fluid changes. Will go for along time if fluid is changed every ~20k miles though.

Air con evaps often burst- dash out job to replace. ($$$$)

Sagging rear susension, & knocking front wishbone joints suggest a hard life- about 250quid to sort.

Condition and evidence of proper maintance is more important than mileage.

Tim..

Reply to
Tim..

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