Jakeswagen
Member
Hi all,
My first post here - Been reading lots of posts from here in my research and finally signed up, glad to be here!
Quick bit of background - I'm now on my third Mk4 Golf PD130 in 7 years. The first one I picked up after selling my 1.8t GTi - Loved the Mk4 platform but wanted better fuel economy as was driving long distances for work, picked up the PD130 and was amazed at amount of torque it offers in every gear, and just all-round driving experience in general. I eventually sold it on for one reason or another but we still have 2 PD130's in the household, one is the mrs' and I've recently picked up another for myself.
My new Golf is great, low mileage for the year (114k) and really good condition. However one thing really bugging me is my average MPG reading has been over 30% lower than my previous Golf with exactly the same driving style and driving routes, coupled with noticeable turbo lag and also lack of power in gears 3-6 from around 2200rpm.
I drive sensibly but not like a grandad - I like to get up to speed quickly where is safe/ possible and then cruise, so go through the gears changing up around 2200-2500rpm, letting the turbo work and provide a good driving experience.
However...when I do drive like a grandad, which is usually on the way to work (stuck behind a grandad!) - I'm changing up the gears at a lower rpm/ not using the turbo, and my mpg results are high and as should be expected with this engine. Therefore I'm fairly certain the low mpg and power is a turbo related fault. Anyway...more info below...
I read an article over on myturbodiesel about low-power causes then decided to get a VCDS license to start running some tests. I have provided the results at the bottom of this post but also here is some more useful information to consider:
Mecanical profile of the car:
All done during my ownership within last 500 miles:
- Contitech timing belt + Meyle HD metal impeller water pump.
- Contitech auxillary belt + Febi tensioner.
- Full service: 5w40 Quantum Platinum oil, Oil Filter, Air Filter, Fuel Filter - All OEM items.
- Coolant temp sensor + thermostat / Coolant flush + new G13 coolant - All OEM.
Other points of interest:
- Clutch + DMF changed @ 87k (no record of brand)
- No fault codes.
- The car is not going into limp mode.
- No smoke when driving or idling.
- Idle is not rough.
- Tyre pressures correct.
- Brakes recently changed and are not binding.
- Car starts and shuts-off perfectly - Ruling out anti-shudder valve issues?
Test Results:
Temperatures from cold-start - Logged using block 007 -
Air Flow (MAF) - Logged using block 003 -
Boost Pressure (MAP) - Logged using block 011 -
Chart 1
Chart 2
....I also did a log for Injection Quantity using block 13 - I let the car idle for a minute or so then worked out the average deviation across that timescale, results are:
13, 1, Injection Quantity, Deviation Cyl. 1. -0.45 mg/str
13, 2, Injection Quantity, Deviation Cyl. 2. -0.13 mg/str
13, 3, Injection Quantity, Deviation Cyl. 3. -0.26 mg/str
13, 4, Injection Quantity, Deviation Cyl. 4. +0.84 mg/str
Cylinder 4 reached as high as +0.96 mg/str during this test. Could this relate to lower MPG? I read a thread on another forum where a guy had cylinder 4 at ~1.2mg/str - He did a diesel purge then posted the results after, the reading had gone down to around 0.6mg/str but he said there was no noticeable improvement in mpg or power, just said the smoothness of the idle was improved.
Since looking at the results of this test I wondered about possible cam wear issues. Looked back through the service history and was gutted to find that the garage that the previous owner took the car to has used 5w30 semi-synthetic oil for the last 2 services....NOT the VW spec 5w40 fully synth as we all know should be used! There was 2 oil changes with this oil and it was used over approx 30k miles... I then took the rocker cover off to inspect the cam lobes/ chamfer and the lifters but thankfully all checked out ok, no wear whatsoever.
Anyway.... I haven't checked for any boost leaks yet. Could the turbo lag and low MPG be caused by a leak?
Invested alot of time and thought into this so far and really want to find the root cause of this issue....help!
Thanks all in advance!
Jake.
My first post here - Been reading lots of posts from here in my research and finally signed up, glad to be here!
Quick bit of background - I'm now on my third Mk4 Golf PD130 in 7 years. The first one I picked up after selling my 1.8t GTi - Loved the Mk4 platform but wanted better fuel economy as was driving long distances for work, picked up the PD130 and was amazed at amount of torque it offers in every gear, and just all-round driving experience in general. I eventually sold it on for one reason or another but we still have 2 PD130's in the household, one is the mrs' and I've recently picked up another for myself.
My new Golf is great, low mileage for the year (114k) and really good condition. However one thing really bugging me is my average MPG reading has been over 30% lower than my previous Golf with exactly the same driving style and driving routes, coupled with noticeable turbo lag and also lack of power in gears 3-6 from around 2200rpm.
I drive sensibly but not like a grandad - I like to get up to speed quickly where is safe/ possible and then cruise, so go through the gears changing up around 2200-2500rpm, letting the turbo work and provide a good driving experience.
However...when I do drive like a grandad, which is usually on the way to work (stuck behind a grandad!) - I'm changing up the gears at a lower rpm/ not using the turbo, and my mpg results are high and as should be expected with this engine. Therefore I'm fairly certain the low mpg and power is a turbo related fault. Anyway...more info below...
I read an article over on myturbodiesel about low-power causes then decided to get a VCDS license to start running some tests. I have provided the results at the bottom of this post but also here is some more useful information to consider:
Mecanical profile of the car:
All done during my ownership within last 500 miles:
- Contitech timing belt + Meyle HD metal impeller water pump.
- Contitech auxillary belt + Febi tensioner.
- Full service: 5w40 Quantum Platinum oil, Oil Filter, Air Filter, Fuel Filter - All OEM items.
- Coolant temp sensor + thermostat / Coolant flush + new G13 coolant - All OEM.
Other points of interest:
- Clutch + DMF changed @ 87k (no record of brand)
- No fault codes.
- The car is not going into limp mode.
- No smoke when driving or idling.
- Idle is not rough.
- Tyre pressures correct.
- Brakes recently changed and are not binding.
- Car starts and shuts-off perfectly - Ruling out anti-shudder valve issues?
Test Results:
Temperatures from cold-start - Logged using block 007 -
Air Flow (MAF) - Logged using block 003 -
Boost Pressure (MAP) - Logged using block 011 -
Chart 1
Chart 2
....I also did a log for Injection Quantity using block 13 - I let the car idle for a minute or so then worked out the average deviation across that timescale, results are:
13, 1, Injection Quantity, Deviation Cyl. 1. -0.45 mg/str
13, 2, Injection Quantity, Deviation Cyl. 2. -0.13 mg/str
13, 3, Injection Quantity, Deviation Cyl. 3. -0.26 mg/str
13, 4, Injection Quantity, Deviation Cyl. 4. +0.84 mg/str
Cylinder 4 reached as high as +0.96 mg/str during this test. Could this relate to lower MPG? I read a thread on another forum where a guy had cylinder 4 at ~1.2mg/str - He did a diesel purge then posted the results after, the reading had gone down to around 0.6mg/str but he said there was no noticeable improvement in mpg or power, just said the smoothness of the idle was improved.
Since looking at the results of this test I wondered about possible cam wear issues. Looked back through the service history and was gutted to find that the garage that the previous owner took the car to has used 5w30 semi-synthetic oil for the last 2 services....NOT the VW spec 5w40 fully synth as we all know should be used! There was 2 oil changes with this oil and it was used over approx 30k miles... I then took the rocker cover off to inspect the cam lobes/ chamfer and the lifters but thankfully all checked out ok, no wear whatsoever.
Anyway.... I haven't checked for any boost leaks yet. Could the turbo lag and low MPG be caused by a leak?
Invested alot of time and thought into this so far and really want to find the root cause of this issue....help!
Thanks all in advance!
Jake.
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