Toyota Surf Conversion - Cooling Problems

VW_Surf

Member
Joined
Jan 17, 2019
Location
Perth, Australia
TDI
Mk5 BKD in Toyota surf
Toyota Surf Conversion - BKD TDI Cooling Problems

Dear Forum,
This is my first post. I have inherited a 94' Toyota Surf with a VW 2.0 BKD TDI 2004 engine. It has been troublesome since I got it. Leaky radiator has been replaced but I'm still having trouble with the cooling system.
Basically after a drive the cooling system gets air in it and expands into the aftermarket overflow container I have fitted that comes off a pipe fitted to the 13 PSI radiator cap. It has the VW plastic reservoir also, I fill this up but after a drive it is empty. The coolant going into the VW reservoir is foamy and bubbly. The exhaust is a bit grey steamy. And sometimes there is steam / smoke coming off the erg cooler.
This made me think it was the ERG cooler and hopefully not the head gasket. So yesterday I bypassed the ERG cooler by sending the incoming coolant passed the ERG cooler and straight into the VW reservoir and snap-tied the control cable going into the valve on the ERG cooler. However the same problems again occurred. I thought maybe it just was a air bubble. So will try again today.
I'm considering ERG delete. But want to positively identify the problem first. The fact that it was smoking means there is something wrong with it fore sure, but is it the only faulty part......
What pressure does the cooling system usually run at? I know that VW usually seal their radiators, well I have a toyota radiator..
I'm curious for thoughts friends! Thanks!
 
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oilhammer

Certified Volkswagen Nut & Vendor
Joined
Dec 11, 2001
Location
outside St Louis, MO
TDI
There are just too many to list....
Yep, sounds like head gasket. I would want to verify proper routing of the cooling system, as VAG products require the circuit for the heater core to always flow (some models, older ones, had a valve that forced the coolant through a bypass hose, but all the newer ones do not).

Toyota, however, will have a coolant valve on most models that stops the flow of coolant through the core. Their engines do not require this circuit to always flow. Usually the valve is there to shut when the temp is on full cold, so the A/C works better and is not fighting against radiant heat bleeding through the HVAC case from the hot core.

Some Ford products sold here (not sure in your area) have a nice vacuum controlled H-valve that works great for VAG engine placement in vehicles that use a heater control valve, as it allows the flow to continue unabated but bypasses the core. I would check this, as I have fixed a few cooked engines on conversions due to this oversight. The engine will got hotter the further back the cylinders go... so #1 will be fine, #2 will show wear, #3 will be bad, and #4 will usually have a melted piston.
 

PickleRick

Veteran Member
Joined
Nov 29, 2017
Location
Greenville sc
TDI
05 GLS BHW sedan 5 speed conversion. BHW Carver SantaCruz in progress
I had a big 3.9l 4 cyl turbo on the stock radiator of both an 86 fj60 and a 67 fj40. Had zero issues cooling. One was idi the other direct injected.

The only isssues i had cooling was with a sbc v8 in the fj40 at hwy rpms above 70. No overdrive.

The stock toyota radiators are well overbuilt and efficient. Id double check the heater core. All my cruisers had a cut off inline when the heat was off.
 

VW_Surf

Member
Joined
Jan 17, 2019
Location
Perth, Australia
TDI
Mk5 BKD in Toyota surf
Thanks for the ideas guys!
I do indeed have a cut off for the heater core, that cable is the last one connected to the egr cooler. I'll try filling the reservoir again today and go for a drive with the heater off and see what happens. I'll have a look at the flow to see if there is a h valve.
I also pinched the vacuum cable to the egr valve on the egr cooler to stop it opening as with no coolent flow maybe it will get too hot? I'm not sure if just pinching that cable is enough to disable the erg system entirely as there seems to be contol valves on the other side of the engine also.
A mechanic I called also said if you disable/delete the egr system without engine ecu remap it can blow the engine. What do you guys think about that?
 

PickleRick

Veteran Member
Joined
Nov 29, 2017
Location
Greenville sc
TDI
05 GLS BHW sedan 5 speed conversion. BHW Carver SantaCruz in progress
On my BHW i used a hose to re route the egr coolant when it was deleted. I have a tune so it doesnt throw a cel. Yours would without a tune.
 

VW_Surf

Member
Joined
Jan 17, 2019
Location
Perth, Australia
TDI
Mk5 BKD in Toyota surf
Took her for a run yesterday with erg valve disabled, coolant bypassed and heater off. Still got air in the system which is not that surprising as even with heater off a leak in the egr cooler would over pressurise the system? Still Confused :(. Going to see a specialist tomorrow who wants 300usd for erg delete + 800usg for ecu tune. I have a background in computers. What cable and software do I need to do the tune myself?
Thanks again!
 

VW_Surf

Member
Joined
Jan 17, 2019
Location
Perth, Australia
TDI
Mk5 BKD in Toyota surf
Ok Success!! I did a full bypass of the EGR cooler ( both the cables to the overflow and to the heater core) and now no more bubbles in the system and coolant level stable and no more overheat! Yay. Now need to look into doing a full delete. I wonder if disabling all the vacuum cables would be sufficient..

I will also order a cable for VCDS so I can play with the settings.
 

VW_Surf

Member
Joined
Jan 17, 2019
Location
Perth, Australia
TDI
Mk5 BKD in Toyota surf
Erg cooler was disgustingly bad! And still is as it is leaching unfiltered exhaust into the engine bay. Did some slow 4wding today after the bypass and we all ended up with a headache from fumes... But at least no more coolant leak or overflow for exhaust gas I cooling system. And looks like, fingers crossed, there is nothing wrong with the head gasket.
Now I need a definitive answer on if blocking the output from engine to erg cooler without a tune will damage my engine as I can't see any reason why it would because I need that erg cooler deleted quick!
 

jimbote

Certified Volkswagen Nut
Joined
Jul 10, 2006
Location
spiral arm, milky way (aka central NC)
TDI
Tacoma 4x4 converted to TDI
physically deleting the egr cooler will not damage the engine but the ecm may retard timing in an attempt to reduce NOX when it detects low egr flow due to the delete
 
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