I'm curious what this job rates on the PITA scale 1 - 10... after reading the Haynes manual seems like a solid 8/10 PITA. Maybe more!?
If you're curious why I'm asking.. read on.
Here's my story in three parts:
PROLOGUE
-2008 Nismo, obviously the VQ40. 282000 km. Owned since 2017.
Current relevant OBDII codes:
-P0011 - Camshaft timing position over-advanced
-P2A00 - Bank 1 O2 Sensor 1 Above threshold
-P0300 - random misfire
-P0306 - cylinder 6 Misfire
PART 1 - 91 Octane Life
p0011 and p2A00 have been faithful friends for several years. Swapped the Cam/Crank sensors, nada. The codes don't seem to impact overall vehicle performance, but over time I've begun to wonder if they are connected to an issue I've had since purchase.. pre-ignition 'ping'. When the weather is warm and I run 87 octane fuel the engine sounds like it's full of gravel when under load - a condition remedied by running 91 (retarded ignition = proper ignition timing). Swapped for new spark plugs, cleaned MAF/intake, etc, etc, problem persists. Seems to point to a problem with the VVT/VCT system.
Confirmed that the solenoid is functioning.. perhaps loss of oil pressure in VVT/VCT system OR stuck actuator on the VVT sprocket actuator. Oh well, keep driving.
PART 2 - Timing Chain Whine / Frontier owner whine
This summer - the much-feared timing chain whine manifests! Awesome. Cool. Maybe this is an excuse to get into the timing case and check out my VVT/VCT problem..! But then after a couple months of driving the whine goes away... strange. Don't get me wrong, the engine is pretty clattery. Perhaps I just blew right through the tensioner guides.. yikes. Oh well. Still driving.
PART 3 - No heat, misfires, and stinky coolant
As the weather turned for the worse it became apparent the the truck wasn't interested in producing heat to the cabin. Only under heavy load would heat actually blow. And look! New codes! p0300 and p0306..
Burped the system, over-filled the reservoir, great - heat is back.. but man, that coolant reeks of combustion gases, and when I'm idling/running in traffic the smell starts to blow into the cabin. Oil currently appears fine, no residue in cap or on dipstick. After a month of daily driving I've still got heat, so no obvious airlocks/coolant loss yet.
SUMMARY - what would you do?
To recap: I've got a suspect VVT/VCT system, suspect timing chain tensioners, and now a suspect head gasket. Vehicle performance is not great but not bad.. rough starts, but chugs along fine once it's warmed. Fuel consumption may be up.. but hard to tell city driving in the winter - it's always seemed erratic.
What could I be missing here?
Plan of action: 1) cylinder compression/leakdown test, 2) block test (combustion gases in coolant), 3) ???
Taking the truck to a shop is out of the question, I'm a student on a tight budget. I'm interested in doing the repairs myself and have the time/shop space to do so.. BUT given the age and mileage of the vehicle, is it worth digging as deep as the head gaskets? I also have some serious work on brakes and suspension in order.
Who else has done this job?
If you're curious why I'm asking.. read on.
Here's my story in three parts:
PROLOGUE
-2008 Nismo, obviously the VQ40. 282000 km. Owned since 2017.
Current relevant OBDII codes:
-P0011 - Camshaft timing position over-advanced
-P2A00 - Bank 1 O2 Sensor 1 Above threshold
-P0300 - random misfire
-P0306 - cylinder 6 Misfire
PART 1 - 91 Octane Life
p0011 and p2A00 have been faithful friends for several years. Swapped the Cam/Crank sensors, nada. The codes don't seem to impact overall vehicle performance, but over time I've begun to wonder if they are connected to an issue I've had since purchase.. pre-ignition 'ping'. When the weather is warm and I run 87 octane fuel the engine sounds like it's full of gravel when under load - a condition remedied by running 91 (retarded ignition = proper ignition timing). Swapped for new spark plugs, cleaned MAF/intake, etc, etc, problem persists. Seems to point to a problem with the VVT/VCT system.
Confirmed that the solenoid is functioning.. perhaps loss of oil pressure in VVT/VCT system OR stuck actuator on the VVT sprocket actuator. Oh well, keep driving.
PART 2 - Timing Chain Whine / Frontier owner whine
This summer - the much-feared timing chain whine manifests! Awesome. Cool. Maybe this is an excuse to get into the timing case and check out my VVT/VCT problem..! But then after a couple months of driving the whine goes away... strange. Don't get me wrong, the engine is pretty clattery. Perhaps I just blew right through the tensioner guides.. yikes. Oh well. Still driving.
PART 3 - No heat, misfires, and stinky coolant
As the weather turned for the worse it became apparent the the truck wasn't interested in producing heat to the cabin. Only under heavy load would heat actually blow. And look! New codes! p0300 and p0306..
Burped the system, over-filled the reservoir, great - heat is back.. but man, that coolant reeks of combustion gases, and when I'm idling/running in traffic the smell starts to blow into the cabin. Oil currently appears fine, no residue in cap or on dipstick. After a month of daily driving I've still got heat, so no obvious airlocks/coolant loss yet.
SUMMARY - what would you do?
To recap: I've got a suspect VVT/VCT system, suspect timing chain tensioners, and now a suspect head gasket. Vehicle performance is not great but not bad.. rough starts, but chugs along fine once it's warmed. Fuel consumption may be up.. but hard to tell city driving in the winter - it's always seemed erratic.
What could I be missing here?
Plan of action: 1) cylinder compression/leakdown test, 2) block test (combustion gases in coolant), 3) ???
Taking the truck to a shop is out of the question, I'm a student on a tight budget. I'm interested in doing the repairs myself and have the time/shop space to do so.. BUT given the age and mileage of the vehicle, is it worth digging as deep as the head gaskets? I also have some serious work on brakes and suspension in order.
Who else has done this job?