vw t25 wbx engine won't turn over after top end rebuild with gearbox fitted

Big lumps of metals and spanners. Including servicing and fluids.

Moderators: User administrators, Moderators

spanishfly
Registered user
Posts: 305
Joined: 09 May 2013, 14:43
80-90 Mem No: 12044
Location: Launceston, Cornwall

vw t25 wbx engine won't turn over after top end rebuild with gearbox fitted

Post by spanishfly »

Feeling despondent frustrated and foolish.
Removed WBX 2.1 dj due to low oil pressure warnings.
Stripped case, very rusty head bolts, snapped some bolts glued in it seems.
Sourced a replacement donor long block from an overheated auto DJ van.
Engine turned freely, no oil in water. Cam ok. 4000 miles apparently.
Replaced heads, valves, push rods, pumps, set tappets on engine stand with the aid of a chopstick through the spark plug holes, TDC plus 1.5 turns, rotated freely. Also replaced pistons, liners, rings, gaskets.... checked flywheel end float all good.

Reconnected gearbox bit of a wiggle and the auto bottom studs seemed shorter so fitted longer ones otherwise no dramas.
Replaced hoses, reconnected everything..... wish I hadn't now. Went to start today tried to turn but hit a dead stop????
Engine rotates backwards but not forwards....... in the morning I'll remove the starter and see if it turns then.
The only slightly odd thing was that cyl n0.1 both valves seemed to be slightly differently set than the other 3?
What have I done wrong?
Last edited by spanishfly on 11 Sep 2021, 21:47, edited 3 times in total.
1987 Westy Joker 1.6TD
1987 Dehler Profi 2+2
1988 Syncro RHD panel
 

Stesaw
Registered user
Posts: 1892
Joined: 10 Aug 2019, 23:30
80-90 Mem No: 17004
Location: Coventry

Re: vw t25 wbx engine won't turn over after top end rebuild with gearbox fitted

Post by Stesaw »

Have you got any pictures? I cannot say I have any experience in an engine doing that.. but it doesn't sound right of course.
You say that block was from an overheated van did you check the Pistons, Barrels, Rods and Cam for damage?
Maybe you've set the TDC on the wrong cylinder when setting tappets?
Last edited by Stesaw on 11 Sep 2021, 19:51, edited 1 time in total.
1985 LeisureDrive 2.1DJ 5 Speed syncro conversion project.
1979 LT 2.0CH Westy project

cobblers
Registered user
Posts: 576
Joined: 21 Feb 2010, 20:50
80-90 Mem No: 17450
Location: Derbyshire

Re: vw t25 wbx engine won't turn over after top end rebuild with gearbox fitted

Post by cobblers »

Did you shim the flywheel to set the endfloat correctly?

User avatar
Oldiebut goodie
Registered user
Posts: 7264
Joined: 18 Apr 2008, 01:19
80-90 Mem No: 11135
Location: Eastern Angle

Re: vw t25 wbx engine won't turn over after top end rebuild with gearbox fitted

Post by Oldiebut goodie »

The only time that I have had an engine do that is when TDC wasn't correct as piston at the top isn't always on compression stroke. Finger over plughole is normal way of checking for compression but any tool for temporary seal that you can feel it with will do.

Hopefully you were only turning it over by hand to check everything first?
1.6D 2019 VW T-Cross
200hp VW T6
1̶Y̶ ̶1̶9̶8̶7̶ ̶H̶i̶-̶t̶o̶p̶ ̶C̶a̶r̶a̶v̶e̶l̶l̶e̶
5̶0̶8̶d̶ ̶M̶e̶r̶c̶

spanishfly
Registered user
Posts: 305
Joined: 09 May 2013, 14:43
80-90 Mem No: 12044
Location: Launceston, Cornwall

Re: vw t25 wbx engine won't turn over after top end rebuild with gearbox fitted

Post by spanishfly »

Thanks, amended post to include the other bits I checked, measured.
I turned it over on the starter but with HT disconnected hope that isn't a disaster? It locked immediately.
If I slack off the tappets and start again finding TDC on 1, might that be a better way forward than dropping the box as some suggested?
Pretty confident clutch and release bearing were refitted and seated correctly.
1987 Westy Joker 1.6TD
1987 Dehler Profi 2+2
1988 Syncro RHD panel
 

Stesaw
Registered user
Posts: 1892
Joined: 10 Aug 2019, 23:30
80-90 Mem No: 17004
Location: Coventry

Re: vw t25 wbx engine won't turn over after top end rebuild with gearbox fitted

Post by Stesaw »

You're on Fuel Injection right?
If so make sure the engine isn't hydrolocked. Check the Fuel pump and assorted bits like the relays if I recall.
1985 LeisureDrive 2.1DJ 5 Speed syncro conversion project.
1979 LT 2.0CH Westy project

User avatar
ajsimmo
Trader
Posts: 2698
Joined: 23 Mar 2009, 14:06
80-90 Mem No: 6542
Location: Isle of Arran
Contact:

Re: vw t25 wbx engine won't turn over after top end rebuild with gearbox fitted

Post by ajsimmo »

Whip the plugs out (just makes it easier) and see if it turns by hand first.

Sent from my ONEPLUS A3003 using Tapatalk


The Campershack - (website paused)
WBX Rebuilds & Upgrades from the beautiful Isle of Arran

spanishfly
Registered user
Posts: 305
Joined: 09 May 2013, 14:43
80-90 Mem No: 12044
Location: Launceston, Cornwall

Re: vw t25 wbx engine won't turn over after top end rebuild with gearbox fitted

Post by spanishfly »

Thanks, yes I did that first thing no difference.
Not to the hard stop which occurs just before TDC going backwards and 120 degrees clockwise from there.
logically the valves were set with the engine on a stand and all seemed fine so the gearbox or starter must be the problem.
If I can find a tool to reach the 8mm allen head will try that next.
Is there any difference between the non auto and auto cases? I hope not? Didn't have both to compare... gearbox out , atleast disconnected by an inch and no difference so looking like clutch?? So annoyed I didn't recheck by turning it over prior to fitting.
Last edited by spanishfly on 12 Sep 2021, 18:38, edited 1 time in total.
1987 Westy Joker 1.6TD
1987 Dehler Profi 2+2
1988 Syncro RHD panel
 

User avatar
R0B
Moderator
Posts: 18855
Joined: 07 Oct 2005, 17:33
80-90 Mem No: 864
Location: Cheshire

Re: vw t25 wbx engine won't turn over after top end rebuild with gearbox fitted

Post by R0B »

There is no difference.
2.1 LPG/Petrol Auto Caravelle

"The difference between genius and stupidity is that genius has its limits"

User avatar
ajsimmo
Trader
Posts: 2698
Joined: 23 Mar 2009, 14:06
80-90 Mem No: 6542
Location: Isle of Arran
Contact:

Re: vw t25 wbx engine won't turn over after top end rebuild with gearbox fitted

Post by ajsimmo »

To rule out valve contact take the rocker shafts off. Sure you didn't drop a small nut or washer into a cylinder? Thinking further, didn't you turn it over by hand on the engine stand when setting up the tappet preloads?

Sent from my ONEPLUS A3003 using Tapatalk

The Campershack - (website paused)
WBX Rebuilds & Upgrades from the beautiful Isle of Arran

spanishfly
Registered user
Posts: 305
Joined: 09 May 2013, 14:43
80-90 Mem No: 12044
Location: Launceston, Cornwall

Re: vw t25 wbx engine won't turn over after top end rebuild with gearbox fitted

Post by spanishfly »

Yes turned over fine replaced everything measured every thing including 'I thought' the compression stroke watched it with a chopstick in the bore.
Yesterday I retraced my steps, loosened rocker rails and checked push rod seating no difference.
Starter out no difference.
Gearbox out, not completely just to the point where I could be sure the edge of the starter cogs were visible, a couple of cm's atleast.
No difference still hit the hard stop which feels a bit like a bolt hitting a dowel? very metal on metal and immovable.

The only thing I fitted after setting the valves was the clutch which along with the flywheel were pre used items with lots of life left. Seems like that was a false economy.
Is it possible to fit the clutch incorrectly or that I fitted the wrong one. Wrong bolts?
BW mention 2 different models for late DJ's.
Are they incompatible somehow?
Thanks for the suggestions everyone?
1987 Westy Joker 1.6TD
1987 Dehler Profi 2+2
1988 Syncro RHD panel
 

User avatar
Oldiebut goodie
Registered user
Posts: 7264
Joined: 18 Apr 2008, 01:19
80-90 Mem No: 11135
Location: Eastern Angle

Re: vw t25 wbx engine won't turn over after top end rebuild with gearbox fitted

Post by Oldiebut goodie »

spanishfly wrote: 13 Sep 2021, 18:03 Yes turned over fine replaced everything measured every thing including 'I thought' the compression stroke watched it with a chopstick in the bore.
Have you double checked that you are using the compression stroke? Watching a chopstick rise doesn't mean that you had the compression stroke, it could have been the exhaust stroke. How did you ascertain that it was the compression stroke anyway?
(I'll leave it to others that know the engine to check that you are on the correct cylinder to start with)
1.6D 2019 VW T-Cross
200hp VW T6
1̶Y̶ ̶1̶9̶8̶7̶ ̶H̶i̶-̶t̶o̶p̶ ̶C̶a̶r̶a̶v̶e̶l̶l̶e̶
5̶0̶8̶d̶ ̶M̶e̶r̶c̶

Stesaw
Registered user
Posts: 1892
Joined: 10 Aug 2019, 23:30
80-90 Mem No: 17004
Location: Coventry

Re: vw t25 wbx engine won't turn over after top end rebuild with gearbox fitted

Post by Stesaw »

Image
That might help as well.
1985 LeisureDrive 2.1DJ 5 Speed syncro conversion project.
1979 LT 2.0CH Westy project

User avatar
T25Convert
Registered user
Posts: 402
Joined: 20 Jun 2009, 09:27
80-90 Mem No: 7819
Location: Chester

Re: vw t25 wbx engine won't turn over after top end rebuild with gearbox fitted

Post by T25Convert »

When you say it turns backwards, is that a full two revolutions, or just back a little from the point it gets stuck? 

If it were me, I'd probably whip the plugs out, and then whip the rockers off (so all valves are closed) and see it it turns over by hand then, saves having to remove engine at this stage.  

If it does go round then, then you would appear to have an issue with the valve train (most likely the 180 degree out trick!).

If it still locks then obviously problem is deeper in. 

Possibly a bit left field but your dizzy drive is in and firmly held down isn't it? Had fun on an old air-cooled with this! 
RIP - George - 1.9DG '85 AutoSleeper Trident - rusted away

George Second - 1.9DG '89 Caravelle

spanishfly
Registered user
Posts: 305
Joined: 09 May 2013, 14:43
80-90 Mem No: 12044
Location: Launceston, Cornwall

Re: vw t25 wbx engine won't turn over after top end rebuild with gearbox fitted

Post by spanishfly »

Thanks, it just turns back a little, 160 degrees rotation in total before hard stops. I did loosen the rails until all push rods span but didn't remove the rails completely. I'll have another go this weekend.

Just possible I confused cylinders 1 and 2 on the dizzy with 2 1 on the Right hand head but pretty sure I would have had to continue turning on the stand in order to do 3 and 4 and certainly span freely at that stage.

No one seems to be pointing at clutch or clutch bolts given the clutch and flywheel were of slightly unknown origin?

I have almost removed the box but would prefer not to go through the pain of wrestling it out and back in again if not necessary....
1987 Westy Joker 1.6TD
1987 Dehler Profi 2+2
1988 Syncro RHD panel
 

Post Reply