How can I make my van faster up hills/ motorway ? PART 2

[BOXY]

On the speedo there are yellow dots to indicate when to change gear. One dot at 20 mph , two at 35 mph, and three at 55 mph. Can your van reach these speeds in the appropriate gear on the flat?

On the way to Gwithian today my van saw 75mph on the speedo on part throttle down the hill at Fraddon and didn't drop below 40mph on any of the hills on the A38 and A30.

[sternal]

you're making me jealous !

makes marks 1st 2nd just about 3rd then you hit 4th gear and no puff ! 56mph on the sat nav on a flat best 58mph...

whats the diagnoses doctor boxy ? dynamite up the exhaust !

[faggie]

sternal it seems weird that it can make nearly 55mph in 3rd then no more in top gear so it must be revving to around 5000 rpm to enable it to make this speed , pity you dont have a rev counter fitted so you can tell us what sort of revs it seems to run out of steam in top , boxy my old van used to pull 100mph in 3rd gear but was slightly tuned

[sternal]

I spoke to a mechanic this eve who was recommended on this site he was really helpful and suggested having the valve timing checked and the exhaust back pressure, he believes this will give the answers...simple check for exhaust back pressure he said when start from cold rev engine and see if you can hold your hand near the exhaust and feel for pressure if none or very little exhaust blocked ! (proper test little bit more complicated) could be why the spark plugs are so black after 10 days running to rich from exhaust back pressure...

Id be laughing if its the exhaust !

[waltraud]

Fascinating thread. I too had a problems with one of these engines but it proved to be low compressikn needing a re build. Itsa bit baffling eh. Im v interested to hear what you find out.

[BOXY]

I don't understand why your van won't do over 55mph if everything that has been checked is ok? My van was able to pull 60 - 65 mph on the flat with a shot inlet valve on one of the cylinders. It took a while to get there but it made it. Is it possible a dragging brake or a wheel bearing could be slowing the van? On the way back from Cornwall this afternoon I was doing 60mph at the top of the hill near Liskeard, knocked the van out of gear, and by the time I was halfway down the hill I was up to 70mph. Have you got a decent steep hill you could free-wheel down (with the engine running) to see it he van can actually go faster then 55mph. That would at least rule out wheels, brakes or invisible anchor.

I can understand the logic in the exhaust causing a a problem if its blocked but the exhaust on most air-cooled vans is normally so rusty there would be plenty of other ways for the gases to get out past the blockage.

[sternal]

once the little terrors are in bed going for a quick drive on the M25...

tried the hill thing even coasting down passed 62mph (never had a long enough hill), brakes are fine there is no binding etc hot wheels smells etc.

silencer (no rust on it) was replaced in 2008 by previous owner when he first got the van...perhaps its faulty and has a 3 ton weight attached to it

[sternal]

absolutely no difference it just seems to pull back...

I received an email from someone on this site suggesting marco mansi who believe it or not is less than a mile from my house, will give him a ring in the morning...I am so bored of this now I didn't want a van that was going to take up this much time/stress, bored of being ripped off by so called specialists mechanics, other mechanics that want to trail and error (thats great if I had an endless supply of £) I only want a van that works that my family and I can travel safely in and enjoy it...Sorry for the rant

[lefty67]

my advice (fwiw) is to chill out and you and your family enjoy your van over the summer. As far as I can make out, the brakes work, so its safe, youve already said the engine runs well its just a little slow when it gets to fourth gear, who cares its still going to get you to the seaside, countryside etc just a little slowly. Ive got an Aircooled, admittedly its a bit faster than yours but i still get on the nerves of mr mondeo. Join the AA and save up some pennies and get the problem sorted over the winter.

[Ralf85]

absolutely no difference it just seems to pull back...

I received an email from someone on this site suggesting marco mansi who believe it or not is less than a mile from my house, will give him a ring in the morning...I am so bored of this now I didn't want a van that was going to take up this much time/stress, bored of being ripped off by so called specialists mechanics, other mechanics that want to trail and error (thats great if I had an endless supply of £) I only want a van that works that my family and I can travel safely in and enjoy it...Sorry for the rant

Or my last recommendation - sell it and get one that goes faster, then the problem goes away. Maybe a T4? Less specialist and possibly even a VW van garage should be able to service it for you.

Next time test the van on the motorway to make sure it can do 70mph+. Simples.

[sternal]

a T4 no thank you !

Selling is an option but then I have to declare to whoever buys it it doesn't go above 55mph !

At least this one seems reliable so far even if it does run like slow saliva running down a window pane ...buying another one is simply buying another problem which could be worse...

[sternal]

Van booked in a week today and going to spend some time with the mechanic (only works on Aircooled) comes recommended from a friend who's taken his split screen there for years, its a bit of a journey to get there but hopefully a worthwhile one... see you in a week

Like my friend said why am I chasing 10mph...he has a point !

[BOXY]

Ask the mechanic to check if the van has still got hydraulic tappets? If the engine has been recon'd it might have had solid lifters fitted instead (my van has). If it has got solid lifters but the tappets have been set up as per the Haynes, the valves will be opening for too long causing a lack of power. Have a look in the engine bay and let me know what the sticker the big red arrow is pointing at is?



It looks suspiciously like the one in my engine bay that I think used to say what the tappet gap should be set to.

[sternal]

Hi

That sticker is this



which means no hydraulic tappets this we know as I have a bill for them being changed 5 yrs. back

its still the original engine according to the V5

very observant mr boxy

[tobydog]

Is'nt that the original VW sticker for hydraulic lifters, saying that the clearances do not need adjusting?

What were they changed to? Any details on the bill?

Mick.