Hey Folks,
I'm at a bit of a loss trying to diagnose my cruiser right now.
Cruiser Specs:
1997 LX450
150k miles
Recent Maintenance:
Valve cover gasket replaced
Coolant flushed with toyota red
PHH replaced
Background:
I've owned the vehicle for 4 years, have done regular oil changes, and have never had any operating issues with it. It just runs like a Toyota.
The issue:
I was driving to work, and upon stopping at a red light, I realized that my cruiser was idling very rough. There was a very consistent rhythmic low frequency "thump - thump - thump" - about twice a second, idling at 800rpm (which is usual). I also had loss of power pulling away from the line and driving up hills. It felt like one cylinder wasn't firing. I returned home to check it out (total of about 10m of driving).
My Diagnosis:
No Check Engine codes stored according to the scan gauge
Pulled wires off of the distributor: They are all sparking, but removing the wire for Cylinder #6 made no change to how it ran. Removing the wire to Cylinder #5 maybe had a slight effect to how it ran, but I couldn't tell.
My Attempted Fixes (no change with each):
I removed plugs 1, 5 and 6 and replaced them with new ones (I chose #1 as a control group as it's usually the best behaved cylinder)
I replaced the plug wires for cylinders 5 & 6 with OEM Densos
I then drove the vehicle to my general family mechanic 10 minutes away for them to take a look at it. They performed a leak down test on cylinder 6 and discovered 18% leakage, with "a little air escaping on both the intake and exhaust side." I'm not too intimately familiar with leak downs, heard of them and know what they get at but have never performed one myself. His hunch is that it seems like a flattened Cam (typically a GM issue) but has never heard of this as an issue with a Cruiser. I wonder if it is indicative of a head gasket issue, or if I have blown a cylinder (which would be a huge bummer).
The mechanic also said that the little bit of air that is leaking is not a clear indication of how poorly the cruiser is running right now - it's really rough.
What do you guys think? Before I green-light anyone to tear into the motor and watch my bill cost upwards of $2000-3000, I want to resolve what I'm getting into. I'm planning on owning the vehicle indefinitely, but want to know what I'm up against.
Thanks all,
Michael
I'm at a bit of a loss trying to diagnose my cruiser right now.
Cruiser Specs:
1997 LX450
150k miles
Recent Maintenance:
Valve cover gasket replaced
Coolant flushed with toyota red
PHH replaced
Background:
I've owned the vehicle for 4 years, have done regular oil changes, and have never had any operating issues with it. It just runs like a Toyota.
The issue:
I was driving to work, and upon stopping at a red light, I realized that my cruiser was idling very rough. There was a very consistent rhythmic low frequency "thump - thump - thump" - about twice a second, idling at 800rpm (which is usual). I also had loss of power pulling away from the line and driving up hills. It felt like one cylinder wasn't firing. I returned home to check it out (total of about 10m of driving).
My Diagnosis:
No Check Engine codes stored according to the scan gauge
Pulled wires off of the distributor: They are all sparking, but removing the wire for Cylinder #6 made no change to how it ran. Removing the wire to Cylinder #5 maybe had a slight effect to how it ran, but I couldn't tell.
My Attempted Fixes (no change with each):
I removed plugs 1, 5 and 6 and replaced them with new ones (I chose #1 as a control group as it's usually the best behaved cylinder)
I replaced the plug wires for cylinders 5 & 6 with OEM Densos
I then drove the vehicle to my general family mechanic 10 minutes away for them to take a look at it. They performed a leak down test on cylinder 6 and discovered 18% leakage, with "a little air escaping on both the intake and exhaust side." I'm not too intimately familiar with leak downs, heard of them and know what they get at but have never performed one myself. His hunch is that it seems like a flattened Cam (typically a GM issue) but has never heard of this as an issue with a Cruiser. I wonder if it is indicative of a head gasket issue, or if I have blown a cylinder (which would be a huge bummer).
The mechanic also said that the little bit of air that is leaking is not a clear indication of how poorly the cruiser is running right now - it's really rough.
What do you guys think? Before I green-light anyone to tear into the motor and watch my bill cost upwards of $2000-3000, I want to resolve what I'm getting into. I'm planning on owning the vehicle indefinitely, but want to know what I'm up against.
Thanks all,
Michael
