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Re: EJ25 DOHC Syncro Heating at 0mph
Posted: 25 Apr 2014, 18:57
by bikermike87
See why I asked for a full swap, fancy starting again, maybe with plug in diagnostics too

Re: EJ25 DOHC Syncro Heating at 0mph
Posted: 25 Apr 2014, 19:41
by syncroandy
bikermike87 wrote:See why I asked for a full swap
Er, yes ! More work to do than I imagined though. That harness does look to have been, er, compromised..
Re: EJ25 DOHC Syncro Heating at 0mph
Posted: 25 Apr 2014, 20:10
by silverbullet
Don't blame the seller. He only removed dead weight scrap iron off the front iirc. The elders of this parish will know who "crafted" the conversion.
E D I T
Doesn't explain the iffy heater symptoms though... unless they skimped on the H-pipe that acts as an automatic bypass when the heater valve is closed? You'll have to go digging to find it mind.
For that matter, does it have an aux heater in the back? Might not be helping matters.
Re: EJ25 DOHC Syncro Heating at 0mph
Posted: 25 Apr 2014, 20:34
by lloydy
Out of genuine interest, why does this overheat thing happen? Does the heater matrix return to a different location on the donor car plumbing? Or does the T3 heater matrix remove more heat? If the latter can a bypass not be fitted to the heater circuit to keep the stat open?
Re: EJ25 DOHC Syncro Heating at 0mph
Posted: 25 Apr 2014, 21:06
by silverbullet
Subaru has a full-flow heater matrix, it mixes hot & cold air for instant temp changes and the coolant bypass circuit is designed accordingly. The VW 025 engine and heater throttles the flow to the heater (1950's tech) and is incompatible with the Subaru engine's coolant system without some sort of passive restricted bypass i.e. rjes H-pipe connector across the heater feed & return hoses.
Re: EJ25 DOHC Syncro Heating at 0mph
Posted: 25 Apr 2014, 21:09
by silverbullet
PS without this mod, coolant flow through the ej engine goes awry if the heater is shut off and they get all hot n bothered.
Re: EJ25 DOHC Syncro Heating at 0mph
Posted: 26 Apr 2014, 00:28
by bikermike87
silverbullet wrote:Don't blame the seller. He only removed dead weight scrap iron off the front iirc. The elders of this parish will know who "crafted" the conversion.
E D I T
Doesn't explain the iffy heater symptoms though... unless they skimped on the H-pipe that acts as an automatic bypass when the heater valve is closed? You'll have to go digging to find it mind.
For that matter, does it have an aux heater in the back? Might not be helping matters.
I don't blame the seller at all, he's been awesome and tried to talk me out of buying it
I'm happy with the van, the parts are there, it just needs a tidy install, which I'm happy to pay for, along with a nice body restore. I have the grounds for a special van and I bought it for a bargain, so all is good. I'm just struggling to find people who can accommodate me
A Syncro ain't cheap and there is probably a good 6-7k to be spent on this.
It does have a heater in the back, bit it blows cold (even when the front is red hot)
Re: EJ25 DOHC Syncro Heating at 0mph
Posted: 26 Apr 2014, 05:57
by lloydy
Have you tried the little lever on the side of the heater?
Re: EJ25 DOHC Syncro Heating at 0mph
Posted: 26 Apr 2014, 08:06
by syncroandy
All good advice. No 'blame' was intended, sorry if I gave that impression. At the moment I'm re-doing some of the leisure wiring on my camper, which was already fitted when I got the van in '03, but had had a go at sorting. I'm cringing a bit at which I'd done previously... One learns a bit from each new task.
Re: EJ25 DOHC Syncro Heating at 0mph
Posted: 26 Apr 2014, 08:11
by bikermike87
lloydy wrote:Have you tried the little lever on the side of the heater?
Inside the van? Sorry, I'm not sure I have secondary one in the back, there are just vents in the back headlining which blow cold, probs just a ducting issue.
I managed to write that post last night after
I'm reasonably impressed with myself.
Re: EJ25 DOHC Syncro Heating at 0mph
Posted: 26 Apr 2014, 11:35
by lloydy
I thought you meant the underseat heater
Re: EJ25 DOHC Syncro Heating at 0mph
Posted: 26 Apr 2014, 11:38
by silverbullet
I think Lloyd was referring to the aux heater control. It has its own valve (like the front heater) but you simply set it "by the season"
Not sure that it even has a control knob as such, just the metal lever on the valve.
If you dont have an aux heater, is this a case of heater lever confusion?
Re: EJ25 DOHC Syncro Heating at 0mph
Posted: 26 Apr 2014, 11:42
by bikermike87
Sorry, no auxiliary heater. Just plain standard caravelle set up.
Re: EJ25 DOHC Syncro Heating at 0mph
Posted: 26 Apr 2014, 11:45
by silverbullet
Going back to the first post: Aidan was bang on the money. But...if you have a full rjes coolant system then this shoud not happen afaik.
Subaru's eh?
Re: EJ25 DOHC Syncro Heating at 0mph
Posted: 26 Apr 2014, 12:47
by bikermike87
So does that mean my engine isn't over heating? It's just that the water pump isn't powerful enough on tickover?
I'm fine about the blowers going cold, I'm just worried about the engine temp gauge. Sorry, I'm still confused on that front. Temp gauge operates fine, apart from 0mph
