I've just finished fitting a Puma 1.7VCT engine to my Mojo, and I'm running it with the standard Ford ECU. It's significantly better than the old 1.25 75bhp 'monster' that was previously fitted, but I've got a bit of a problem with it and i was hoping you guys could help.

The cylinder head temperature goes up to 89-90 degrees within a mile or two (normal), and then the thermostat opens because I can see the radiator temperature climbing (I've got 2 temperature gauges). All ok so far. But, when the radiator temperature reaches about 90 degrees, the cylinder head temperature and radiator temperature both start climbing again and they got to about 97 degrees the other day before I found somewhere to pull over and let everything cool down. The last thing I wanted to do was to blow a head gasket... The engine was very hot, and the exhaust was tinking away merrily. After limping home, I checked the following:

Airlocks - none.
Thermostat opening - fine, but swapped it anyway.
Waterpump - a bit tight, so swapped for another known working one.
Flushed the radiator and engine - all flowing freely and clean.

I then read the diagnostic codes from the Ford ECU and it showed a DTC error of P0172 - system too rich. I'm guessing that the ECU has read a rich condition and tried to lean the engine off as much as possible which has caused it to run hot?

I'm in the process of changing the MAF sensor and air filter but does anyone have any bright ideas of what else to check? I've got a track day in 3 weeks and I can only go about 5 miles at the moment before I need to stop and let everything cool down so I'd like to get this sorted asap!

Any suggestions welcomed!

Ed.

PS: Tried getting the spark plugs out to see if it was actually running rich or lean but being a Zetec SE, they're deep in the cylinder head and as tight as a**holes, and I really don't want to snap one off in the head. They're soaking in WD40 at the moment.

Is the fan kicking in and running the right way?

I had a lot of overheating issue with my build, it would sit and idle all day without overheating, but on the move it overheated, my issues were eventually traced to the fan running the wrong way and needing to force more air through the rad (was all going around rather than through)

97 degrees doesn't sound that hot, what is the normal operating temp of the engine?

[Edited on 3/5/10 by phoenix70]

Check the radiator outlet/water pump inlet temp.

Also as above a a lot engines operate at over 100c these days.

If it worries you you might want to consider ditching the original thermostat and fitting the LandRover/MG-Rover PRT thermostat that will hold the temperature rock stead at 91 if you have a big enough rad & fan.

[Edited on 3/5/10 by britishtrident]

Hi,

The fan is the right way round, it's mounted on the rear of the rad and pulling air through as per the previous installation. With the old engine, the fan kicked in at 104 degrees and only when stationary (never while running). I'll double check what the fan does on the new engine once I've got it all back together.

From experience, these engines should stay at 89-93 degrees whilst on the move and only start heating up when stationary.

When my engine started heating up, I was doing 'approximately' 70 on the A14 and the temperature started climbing quite fast at about 1 degree every 5-10 seconds and did not appear to have any intention of slowing down, so I pulled off at the next junction and parked up as soon as possible. I cleared the error code from the ECU and went out again - the code came back and the temperatures started to climb again after a few miles.

I'm fairly confident that the cooling system is doing what it can, but the engine jsut gets too hot and then and then keeps getting hotter. The rad is the standard Polo one and should be fine for 130bhp.

Ed.

I'll check the temperatures of the radiator outlet next time I fire it up.
BTW: The thermostat is 82 degrees although there is a Ford service bulletin for the Focus that specifies a 74 degree version...

quote:

---

Originally posted by Madinventions
I've just finished fitting a Puma 1.7VCT engine to my Mojo, and I'm running it with the standard Ford ECU. It's significantly better than the old 1.25 75bhp 'monster' that was previously fitted, but I've got a bit of a problem with it and i was hoping you guys could help.

The cylinder head temperature goes up to 89-90 degrees within a mile or two (normal), and then the thermostat opens because I can see the radiator temperature climbing (I've got 2 temperature gauges). All ok so far. But, when the radiator temperature reaches about 90 degrees, the cylinder head temperature and radiator temperature both start climbing again and they got to about 97 degrees the other day before I found somewhere to pull over and let everything cool down. The last thing I wanted to do was to blow a head gasket... The engine was very hot, and the exhaust was tinking away merrily. After limping home, I checked the following:

Airlocks - none.
Thermostat opening - fine, but swapped it anyway.
Waterpump - a bit tight, so swapped for another known working one.
Flushed the radiator and engine - all flowing freely and clean.

I then read the diagnostic codes from the Ford ECU and it showed a DTC error of P0172 - system too rich. I'm guessing that the ECU has read a rich condition and tried to lean the engine off as much as possible which has caused it to run hot?

I'm in the process of changing the MAF sensor and air filter but does anyone have any bright ideas of what else to check? I've got a track day in 3 weeks and I can only go about 5 miles at the moment before I need to stop and let everything cool down so I'd like to get this sorted asap!

Any suggestions welcomed!

Ed.

PS: Tried getting the spark plugs out to see if it was actually running rich or lean but being a Zetec SE, they're deep in the cylinder head and as tight as a**holes, and I really don't want to snap one off in the head. They're soaking in WD40 at the moment.

---

Have you moved the lambda sensor in the exhaust?

As above can you swap the lambda or fit a WB to check.

i run a a se engine and have also had overheating issues since day one, although mine is a 1.6,

Thanks for all the replies guys! That's the great thing about this forum - you're never alone when faced with a problem!

I've just pulled the lambda sensor from the 1.25 engine which I know works well and I'll swap this with the 1.7 when I get the exhasut shields off. I'm wondering if the 1.7 sensor may be contaminated? I've got a couple of sensors from a 1.6 as well but these look different to the 1.25 and 1.7 versions. On all these engines, the lambda sensor is right at the top of the exhaust manifold about 4-5 inches from the exhaust ports so it's far too hot for a WB sensor. The cat is immediately after the manifold so there isn't really anywhere to fit a WB with my current exhaust setup unfortunately.

Still can't get the bl**dy spark plugs out!

Ed.

[Edited on 3/5/10 by Madinventions]

whats the fault code ?

P0172 - system too rich. This is the freeze frame data:

Fuel system status: CL fault
Cal load: 41.2%
Coolant: 84C
Short term fuel trim: -3.9%
Long term fuel trim: -21.9%
Rpm: 2114
Speed: 26

The DTC has been triggered by the -21.9% ltft setting which means that the ECU has leaned the engine out as much as possible and it has decided that this is a problem. This data is from the second test, not the 70mph A14 saga which is why the speed is much lower!

Ed.

[Edited on 3/5/10 by Madinventions]

Just for completeness, I'm also getting DTC P0443 (EVP valve malfunction) but that's because I haven't fitted the whole EVP system that Ford use and the valve in question is missing.

This DTC (P0443) was present on the last engine install as well and didn't cause any problems. Never had any other fault codes.

[Edited on 3/5/10 by Madinventions]

Well, I managed to finally get the spark plugs out (NGK PTR5A's...)


Spark plug

If that's running rich, I'll be a monkey's buttock! That plug has been running hot!
All 4 are the same.


I'll put it all back together and swap out the O2 sensor...

Ed.

Here's the O2 sensor from the 1.7 alongside the working one from the 1.25.

lambda sensors
The top one is the 1.7 and has a hard white deposit all over it (looks a lot browner in the photo, it's actually a creamy white colour)... According to the bosch website this is contaminated and is knackered . So glad I've got spares lying around!

More to follow...
Ed.

My eec-v gives three fault codes but thats because ive ditched all the evap crap.

New Lambda should sort it then.

Hav'nt used any silicone bassed sprays to help find leaks have you ?

Hi Wasa,

I've not used any silicone sprays or fuel additives with this engine, but I've got no idea what the previous owner may or may not have done to it... It does look like classic silicone contamination though doesn't it? I'm hoping the new sensor will cure it Fingers crossed...

What are your error codes? I only get P0443, no other EVAP related codes.

Ed.

erm I did write them down I will se if I can find them.

Do you have the speedo sensor hooked up ?

I am wondering if I will get any problems other than cutting fuel on over run to stop it poping and a little better on mpg.

P0443
Evap Emission Control System Purge Control Circuit Malf.

P1401
DPFE Circuit High Input

P1409
EVR Control Circuit Malfunction

Yep - speedo sensor is connected to the ECU and works fine.

Can't say I noticed any issues with EVAP missing on the previous engine, but then I'm not entirely sure when it is suppoesed to be activated and what effects it is supposed to have?

Ed.

PS: New MAF sensor is now installed on a new bracket, just needs wiring in. New O2 sensor is fitted. Just need to fill the coolant and do an idle test with the laptop connected.

Ah - I think you've got a much newer engine than mine (late 1999) because I don't appear to have the DPFE or EVR parts. Does it run ok?

Ed.

97~98 mondeo. some models didnt have it all.

Not got it on the road or had it on the rollers yet. Mine runs fine and another one ive done also runs fine.

Well, I think this might be sorted now. I changed the O2 sensor, and been out for a short blat. Even with 8 miles of driving and 4 laps of the roundabout the temperature didn't go over 91 degrees and stayed at 89-90 for most of the time. The long term fuel trim in the ECU hasn't changed much yet so the ECU doesn't appear to be leaning the mixture off just yet. A few more miles on the clock should show if it's finally sorted.

Thanks for all the replies!