Technical questions and answers about the Mazda Bongo
Moderators: Doone, westonwarrior
-
teenmal
- Supreme Being
- Posts: 3656
- Joined: Thu Mar 27, 2008 6:08 pm
- Location: north lanarkshire
Post
by teenmal » Tue Dec 02, 2014 11:49 pm
jimmo62 wrote:Did you get a new belt? If so I would try fitting it and then turning the engine over with a spanner on the crankshaft - if it jams you have bent/stuck valves. I'm not convinced about the cams being hard to turn if they have hydraulic actuators as the valves may only get opened once there's hydraulic pressure - so with the engine off they may be easy to turn even if not damaged - perhaps someone with more detailed knowledge on how these work could comment? I'd say for the cost of a new belt it would be worth trying before spending a lot on taking off the heads or getting a new engine.
You need to be very cautious if you try this operation as the HLA are not functional (as you have mentioned)and will give a false test.
-
mr_marrakesh
- Junior Bongonaut
- Posts: 20
- Joined: Sun Sep 20, 2015 11:24 am
Post
by mr_marrakesh » Sun Feb 17, 2019 10:34 pm
Hi there, the cam belt snapped on my V6 2001 Bongo while I was driving at about 30 miles an hour. I'm trying to work out if it's likely to have sustained any engine damage or not so I can decide if it's worth getting the garage to bother trying to fit a new cam belt or whether I should be looking at getting a new engine.
The general consensus on this forum seems to be that the V6 is a non interference engine which gives me hope but the only posts I could find from anyone who's actually snapped a cam belt are this one and one from 2010 (
https://www.igmaynard.co.uk/bongo/forum ... =3&t=42072) and from what I could gather, both of these had engine damage.
Is there anyone out there who has snapped a cam belt on a V6 and not had any engine damage and been able to replace the cam belt and drive away?
Thanks, Henry
2001 V6 LPG AFT full side conversion
-
Bob
- Supreme Being
- Posts: 15255
- Joined: Wed Oct 17, 2007 12:54 pm
- Location: North Somerset
Post
by Bob » Sun Feb 17, 2019 11:35 pm
Rotten luck.
The 2 Ltr 4 cylinder is a non interference engine, I'm not sure that the V6 is.
Sorry that won't help.
-
Flanners
- Bongolier
- Posts: 421
- Joined: Tue Oct 31, 2017 4:11 pm
Post
by Flanners » Mon Feb 18, 2019 8:23 am
Bob just had a read of a few threads and cannot find a definitive answer with regards to the engine being interference or not for both the 2.0 and V6; lots of conflicting comments, I would love to know for peace of mind.
2002 2.0 Aero with Outback Conversion and Roof Top Tent
-
g8dhe
- Supreme Being
- Posts: 10180
- Joined: Sun Apr 13, 2008 10:06 pm
- Location: Worthing, West Sussex.
-
Contact:
Post
by g8dhe » Mon Feb 18, 2019 10:33 am
Hopefully Lorna can comment with experience from Allan ?
As I understand it the V6 is non-interference, but there have been occasional reports of damage, maybe it was more than a simple cam belt snapping in those situations ?
-
Ian
- Supreme Being
- Posts: 5885
- Joined: Wed Jun 09, 2004 2:47 pm
- Location: Bongo Mission Control
Post
by Ian » Mon Feb 18, 2019 11:01 am
Non-interference as far as I can tell. Proof: member's cam belt snapped on V6 Bongo 2 weeks ago in Dorset. Taken to RD Motors in Poole. Everything checked, no damage to engine, new cam belt installed, everything back to normal.
668. The Neighbour of The Beast.
-
mr_marrakesh
- Junior Bongonaut
- Posts: 20
- Joined: Sun Sep 20, 2015 11:24 am
Post
by mr_marrakesh » Mon Feb 18, 2019 11:09 am
Right, well I’ll go for the cam belt change. Thanks for the input and I’ll update everyone with the results.
2001 V6 LPG AFT full side conversion
-
Doone
- Supreme Being
- Posts: 2839
- Joined: Sun Jul 04, 2004 10:58 am
- Location: Devon
-
Contact:
Post
by Doone » Mon Feb 18, 2019 3:50 pm
The V6 is listed as a non-interference engine. The majority (with snapped belts) that Allan (Allans Vehicle Services) has repaired have been fine.
But he's had 4 in with snapped belts that did have engine damage. (This is surprising, but they're all on record and can be verified.)
Be reassured that the odds are in your favour, it's most likely that the engine will be ok.
Allan's closed. We recommend PGS (Plymouth Garage Services) or Mayflower Auto Services in Plymouth.
-
Bob
- Supreme Being
- Posts: 15255
- Joined: Wed Oct 17, 2007 12:54 pm
- Location: North Somerset
Post
by Bob » Mon Feb 18, 2019 5:39 pm
Possible where there's engine damage a valve dropped first causing the belt to break?
Chicken - Egg...
-
Bonneville
- Bongolier
- Posts: 155
- Joined: Wed Mar 28, 2018 10:50 am
Post
by Bonneville » Tue Feb 19, 2019 10:21 am
Drained HLA's do not stop valves opening. They take up a (typical) .20 clearance so all you get is noise while they pump up. There should be resistance to turning the cam by hand even if the HLA's are new or fully drained.
On the subject of V6 interference, all it needs is for someone to measure the valve extension and the depth of pocket in the piston then add the gasket thickness and this could be definitively resolved. I did this on my 2.0 as the pistons are from the 16V engine and have 2 exhaust pockets for only 1 exhaust valve in the head so I wanted to be sure. I don't have a V6 to play with.
The reason this is important is that just putting a cambelt on and assuming it's OK if it runs is bad practice. I had an R1 engine in here that had kissed a valve (5 per cylinder) but the damage was very slight (just a gentle bend causing the valve to be slightly off-seat). That engine ran well at revs but had a slightly uneven idle. If the V6 is an interference engine, the only way to be safe would be to pull the heads and check.
-
mr_marrakesh
- Junior Bongonaut
- Posts: 20
- Joined: Sun Sep 20, 2015 11:24 am
Post
by mr_marrakesh » Thu Apr 11, 2019 8:21 am
Hi, sorry, meant to reply earlier. I had the cam belt changed and everything went fine and the Bongo is now up and running, no problems. Thanks for everybody's help.
2001 V6 LPG AFT full side conversion
-
Bob
- Supreme Being
- Posts: 15255
- Joined: Wed Oct 17, 2007 12:54 pm
- Location: North Somerset
Post
by Bob » Thu Apr 11, 2019 12:51 pm
Result.