08 LE - Broken radiator causes overheating and cylinder 2 misfire P0302

1721 Views 28 Replies 11 Participants Last post by benmp, 4 mo ago

benmp

Discussion Starter · 4 mo ago

Hello all,

2008 LE, 145,000 miles. After driving on the highway normally for 30 minutes last Saturday, I got check engine, VSC and TRAC OFF lights on when I started it again. I used OBD2 scanner at Autozone and got P0302 code. At first I thought it was because of ignition coils. However, the lights were still on after I replacing the front three coils (cylinder 2,4,6).

Took it to my mechanic for futher check. He found radiator crack, which caused coolant leaking, engine overheating, blown head gasket and cylinder #2 misfire. Some coolant was found in the cylinder. I asked why the temperature gauge didn't show anything wrong while driving, he told me the gauge would lie sometimes (he explained the reason but I didn't understand).

He quoted $2637 in total for fixing everything, including rebuilding cylinder head, replacing head gasket, water pump, radiator, thermostat, spark plug, ignition coils (the new coils I bought), and changing oil and coolant.

Any thoughts on the quote? How do you think spending such money on this old van? I bought it last year for $8900 and drove it for 10,000 miles. But I guess I would also loss a lot if I sell it now with these problems.

Want to share this experience to you. Thank you!

1 - 20 of 29 Posts

slothman

· #2 · 4 mo ago

ok, if you have a blown head gasket, you will have the following:

overheating
milky looking oil
Low coolant level
white smoke from exhaust
low compression on cylinder

if you DON"T have any of those, the mechanic is trying to rob you

you need to reset the code with a scanner, or disconnect the battery. did you happen to replace the spark plugs? If not, I would start there (always go cheap first)

the code could also be a failing fuel injector. I would first HIGHLY recommend a fuel injector cleaner, and this is the BEST : https://www.amazon.com/BG-44K-System-Cleaner-Enhancer/dp/B00DDVU6EI/ref=sr_1_6?crid=2E0ZAE2XAZ6JS&keywords=bg+fuel+injector+cleaner&qid=1674013727&sprefix=BG+fuel+in,aps,155&sr=8-6

run that cleaner, drive a couple hundred miles, and then install fresh plugs. That is worth a shot, before paying all that money.

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benmp

Discussion Starter · #3 · 4 mo ago

slothman said:
ok, if you have a blown head gasket, you will have the following:

overheating
milky looking oil
Low coolant level
white smoke from exhaust
low compression on cylinder

if you DON"T have any of those, the mechanic is trying to rob you

you need to reset the code with a scanner, or disconnect the battery. did you happen to replace the spark plugs? If not, I would start there (always go cheap first)

the code could also be a failing fuel injector. I would first HIGHLY recommend a fuel injector cleaner, and this is the BEST : https://www.amazon.com/BG-44K-System-Cleaner-Enhancer/dp/B00DDVU6EI/ref=sr_1_6?crid=2E0ZAE2XAZ6JS&keywords=bg+fuel+injector+cleaner&qid=1674013727&sprefix=BG+fuel+in,aps,155&sr=8-6

run that cleaner, drive a couple hundred miles, and then install fresh plugs. That is worth a shot, before paying all that money.

Thank you. Yes, I repalced the spark plugs last year. I also reset the code with the scanner that day but the lights came back after 5 minutes driving.

I found lots of pink stains under the hood. It seemed the coolant sprayed out. The coolant level became a little lower. I also found white smoke from exhaust. When I drove home with check engine lights blinking, I felt the van was idling rough and the temperature went quite high. I never saw temp gauge above middle previously. But I can't tell whether the oil is milky. Will try the cleaner. Thanks!

BillG

· #4 · 4 mo ago

slothman said:
ok, if you have a blown head gasket, you will have the following:

overheating
milky looking oil
Low coolant level
white smoke from exhaust
low compression on cylinder

if you DON"T have any of those, the mechanic is trying to rob you

you need to reset the code with a scanner, or disconnect the battery. did you happen to replace the spark plugs? If not, I would start there (always go cheap first)

the code could also be a failing fuel injector. I would first HIGHLY recommend a fuel injector cleaner, and this is the BEST : https://www.amazon.com/BG-44K-System-Cleaner-Enhancer/dp/B00DDVU6EI/ref=sr_1_6?crid=2E0ZAE2XAZ6JS&keywords=bg+fuel+injector+cleaner&qid=1674013727&sprefix=BG+fuel+in,aps,155&sr=8-6

run that cleaner, drive a couple hundred miles, and then install fresh plugs. That is worth a shot, before paying all that money.

That's not necessarily true. You can have a blown head gasket which lets exhaust into the coolant and will give no signs other than an occasional bubble in the overflow tank and you'll never know. OR you could have small coolant leak, which causes an overheating condition, which warps the head, blows the gasket, lets exhaust gas into the coolant which boils, over-pressures the radiator, blowing out the plastic tank where the small leak was and spraying coolant all over your engine bay. Assuming the mechanic is a crook is a bad way of doing internet diagnostics. Based on the information provided (coolant leak, misfire, coolant in the cylinder), it's almost certain that this mechanic is reliable and trustworthy.

@benmp $2637 is an exceptionally great price for a new head, gasket, and all the other service you're considering. When it comes down to it, in its current condition, the van is probably worth a few hundred dollars. If you traded it in through one of those push-pull-tow deals, you might get a couple thousand trade-in value for it, but those are harder to come by these days. So, is the van worth $2637 to you? Condition is everything. You could need another $2000 worth of work on it in 6 months, if it has a bunch of deferred maintenance to be done. OR it could need nothing else but oil changes and tires for another 2 years.

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sixto

· #5 · 4 mo ago

Did the shop confirm no work is needed on the rear cylinder head? Are you close to needing a timing belt?

The temp gauge isn’t linear which is a nice way of saying it isn’t accurate. When the gauge in our ‘04 goes above half, the AC button flashes indicating a problem with the AC system. That’s our alert to overheating. It’ll throw a check engine light if the coolant doesn’t get to operating temp in 30min. That’s worth telling the driver. That the engine’s hot enough to destroy itself? Everything but the temp gauge flashes.

Sixto
‘04 LE FWD 207K miles

benmp

Discussion Starter · #6 · 4 mo ago

sixto said:
Did the shop confirm no work is needed on the rear cylinder head? Are you close to needing a timing belt?

The temp gauge isn’t linear which is a nice way of saying it isn’t accurate. When the gauge in our ‘04 goes above half, the AC button flashes indicating a problem with the AC system. That’s our alert to overheating. It’ll throw a check engine light if the coolant doesn’t get to operating temp in 30min. That’s worth telling the driver. That the engine’s hot enough to destroy itself? Everything but the temp gauge flashes.

Sixto
‘04 LE FWD 207K miles

Thank you. He told me it was just cylinder #2. My 2008 has a timing chain, not belt.

I see, I did see the temp gauge above half after getting check engine lights blinking, so I drove home very carefully that night. But before I got check engine light on, when I was driving on the highway that morning normally, I didn't see anything wrong. The temp gauge was stable below half and the coolant level was a little lower than the high level (maybe lower than before but still at a reasonable level). Don't know if there is a better way to monitor & prevent overheating.

benmp

Discussion Starter · #7 · 4 mo ago (Edited)

BillG said:
That's not necessarily true. You can have a blown head gasket which lets exhaust into the coolant and will give no signs other than an occasional bubble in the overflow tank and you'll never know. OR you could have small coolant leak, which causes an overheating condition, which warps the head, blows the gasket, lets exhaust gas into the coolant which boils, over-pressures the radiator, blowing out the plastic tank where the small leak was and spraying coolant all over your engine bay. Assuming the mechanic is a crook is a bad way of doing internet diagnostics. Based on the information provided (coolant leak, misfire, coolant in the cylinder), it's almost certain that this mechanic is reliable and trustworthy.

@benmp $2637 is an exceptionally great price for a new head, gasket, and all the other service you're considering. When it comes down to it, in its current condition, the van is probably worth a few hundred dollars. If you traded it in through one of those push-pull-tow deals, you might get a couple thousand trade-in value for it, but those are harder to come by these days. So, is the van worth $2637 to you? Condition is everything. You could need another $2000 worth of work on it in 6 months, if it has a bunch of deferred maintenance to be done. OR it could need nothing else but oil changes and tires for another 2 years.

Thanks for the input. I plan to fix it since it's my only vehicle now. It's generally in good condition. I changed all the fluids last year and replaced 4 brake pads. Hope it can last longer.

A problem puzzling me is that how can I prevent it happening again. Before getting the engine problem, I drove on the highway and thought everything was good. The temp gauge was stable below half and the coolant level was between low and high (maybe lower than before but still at a reasonable level). The small crack on the radiator is hard to notice for me. Thank you.

Reactions: 1

sixto

· #8 · 4 mo ago

A new radiator should last a long time. The t-fittings for the rear heater could go next. It shouldn’t add much to the total cost to have those replaced when they’re repairing the cylinder head. Toyota coolant leaves pink crystals when exposed to air so leaks are that much easier to notice. I think I mentioned checking coolant level in the engine, not just looking at the level in the reservoir.

There are oil lines with rubber segments that Toyota redesigned in all metal. I’d replace them if they’re the type with rubber.

Sixto
‘04 LE FWD 207K miles

Reactions: 1

cougarhound

· #9 · 4 mo ago

That's a very good price and yes I would pay him to fix it. Is this guy anywhere near Boston. I need a good mechanic. Lol.

Also I'm not sure why you continued to drive it if you saw coolant stains and White smoke coming out of the exhaust. Your temp gauge should have definitely been red.

Reactions: 1

BillG

· #10 · 4 mo ago

benmp said:
A problem puzzling me is that how can I prevent it happening again. Before getting the engine problem, I drove on the highway and thought everything was good. The temp gauge was stable below half and the coolant level was between low and high (maybe lower than before but still at a reasonable level). The small crack on the radiator is hard to notice for me. Thank you.

It's a hard task to accomplish. The Gen2 Sienna has plastic ends of the radiator which crack/leak. It has a plastic pipe/thermostat cover which can crack/leak. There are plastic coolant hose tees which can crack/leak. Finally, the valley pan (I think only the 3.3L had this issue) isn't sealed particularly well and can leak. Most all of these leaks are one of two types... The slow pinhole which drips a couple drops of coolant somewhere totally out of sight OR the catastrophic failure that dumps all your coolant in one shot typically while driving. The slow leak can be remediated by checking the coolant level in the radiator at least monthly but weekly isn't too often. If you have to add any over the course of a year, you have a leak. The catastrophic failure can only be eliminated through upgrade and/or routine replacement. @sixto figured out that the 1MZ used a 2-piece metal pipe/thermostat cover which can be sourced from a junkyard or purchased new from the dealer. Someone else (sorry, can't remember who) replaced the plastic tees with brass plumbing tees. The radiator can be replaced with an all-aluminum aftermarket one, but I have heard of fitment/bracket issues depending on model year and production month. If it works for you, that's probably the best option. Otherwise, you should expect to replace the radiator with a Denso or Toyota branded one every 10 years or so. If you're past the 10-year mark, you're on borrowed time. Really, it's a design/engineering issue which probably falls under the "planned obsolescence" heading. They WANT your vehicle to fail catastrophically at a certain point so they can sell more vehicles.

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sixto

· #11 · 4 mo ago

The temp sensor reads coolant. Air, not so well. When the coolant level in the block drops to where there’s insufficient coolant flowing around the temp sensor, the gauge stops rising.

@BillG, yup, I have a 1MZ lower radiator hose fitting and thermostat fitting. Also brass PEX tees for the rear heater hoses.

Sixto
‘04 LE FWD 207K miles

Reactions: 2

Roader

· #12 · 4 mo ago

benmp said:
Took it to my mechanic for futher check. He found radiator crack, which caused coolant leaking, engine overheating, blown head gasket and cylinder #2 misfire.

I think your mechanic might be assuming too much. I don't doubt his diagnosis of a bad head gasket but 2GR-FEs have been know to have that problem. Not frequently, but it does happen. It could be that the bad HG was the main reason for coolant loss, not a cracked radiator, especially considering you never saw the temp gauge go into the red zone but instead just noticed the loss of cabin heat. A bad HG can allow coolant to slowly but surely get sucked into the combustion chamber with no other apparent symptoms. Don't beat yourself up over not noticing that.

The very good news it that it's the front head. And $2637 is, what, much less than one year's worth of new car payments? 145K is pretty low miles.

supra129

· #13 · 4 mo ago (Edited)

How often do you check your vehicle fluids? Maybe you could of caught it before this happened. Make it a habit to check on them weekly or monthly, it does have 145k miles. I do weekly checks by opening the hood and quickly scanning the fluid levels in the power steering reservoir, coolant reservoir, and brake master cylinder reservoir. I also check the oil level. If anything is low then there may be a potential problem.

Reactions: 3

cougarhound

· #14 · 4 mo ago

I have to check my coolant because I noticed that the reservoir levels drop every oil change. My guess is that there is a slow leak into the cylinders from a degrading head gasket. I have 240,000 miles on my engine and I will continue drive it and top it off until something blows up. Lol.

Reactions: 1

benmp

Discussion Starter · #15 · 4 mo ago

sixto said:
A new radiator should last a long time. The t-fittings for the rear heater could go next. It shouldn’t add much to the total cost to have those replaced when they’re repairing the cylinder head. Toyota coolant leaves pink crystals when exposed to air so leaks are that much easier to notice. I think I mentioned checking coolant level in the engine, not just looking at the level in the reservoir.

There are oil lines with rubber segments that Toyota redesigned in all metal. I’d replace them if they’re the type with rubber.

Sixto
‘04 LE FWD 207K miles

I see, that's very helpful. Thank you!

benmp

Discussion Starter · #16 · 4 mo ago

cougarhound said:
That's a very good price and yes I would pay him to fix it. Is this guy anywhere near Boston. I need a good mechanic. Lol.

Also I'm not sure why you continued to drive it if you saw coolant stains and White smoke coming out of the exhaust. Your temp gauge should have definitely been red.

Lol, we're in Texas.

Yeah, it's my fault that I wanted to get back home soon. I didn't realized seriousness and thought I could just rely on the temp gauge since it flucutated between 1/2 to 3/4 but not red.

Reactions: 1

benmp

Discussion Starter · #17 · 4 mo ago

BillG said:
It's a hard task to accomplish. The Gen2 Sienna has plastic ends of the radiator which crack/leak. It has a plastic pipe/thermostat cover which can crack/leak. There are plastic coolant hose tees which can crack/leak. Finally, the valley pan (I think only the 3.3L had this issue) isn't sealed particularly well and can leak. Most all of these leaks are one of two types... The slow pinhole which drips a couple drops of coolant somewhere totally out of sight OR the catastrophic failure that dumps all your coolant in one shot typically while driving. The slow leak can be remediated by checking the coolant level in the radiator at least monthly but weekly isn't too often. If you have to add any over the course of a year, you have a leak. The catastrophic failure can only be eliminated through upgrade and/or routine replacement. @sixto figured out that the 1MZ used a 2-piece metal pipe/thermostat cover which can be sourced from a junkyard or purchased new from the dealer. Someone else (sorry, can't remember who) replaced the plastic tees with brass plumbing tees. The radiator can be replaced with an all-aluminum aftermarket one, but I have heard of fitment/bracket issues depending on model year and production month. If it works for you, that's probably the best option. Otherwise, you should expect to replace the radiator with a Denso or Toyota branded one every 10 years or so. If you're past the 10-year mark, you're on borrowed time. Really, it's a design/engineering issue which probably falls under the "planned obsolescence" heading. They WANT your vehicle to fail catastrophically at a certain point so they can sell more vehicles.

Got it, very helpful. Thanks!

Reactions: 1

benmp

Discussion Starter · #18 · 4 mo ago

supra129 said:
How often do you check your vehicle fluids? Maybe you could of caught it before this happened. Make it a habit to check on them weekly or monthly, it does have 145k miles. I do weekly checks by opening the hood and quickly scanning the fluid levels in the power steering reservoir, coolant reservoir, and brake master cylinder reservoir. I also check the oil level. If anything is low then there may be a potential problem.

I used to check them maybe every two / three months. Yeah, I defnitely need to check them weekly in the future.

Reactions: 1

benmp

Discussion Starter · #19 · 4 mo ago

Roader said:
I think your mechanic might be assuming too much. I don't doubt his diagnosis of a bad head gasket but 2GR-FEs have been know to have that problem. Not frequently, but it does happen. It could be that the bad HG was the main reason for coolant loss, not a cracked radiator, especially considering you never saw the temp gauge go into the red zone but instead just noticed the loss of cabin heat. A bad HG can allow coolant to slowly but surely get sucked into the combustion chamber with no other apparent symptoms. Don't beat yourself up over not noticing that.

The very good news it that it's the front head. And $2637 is, what, much less than one year's worth of new car payments? 145K is pretty low miles.

Thanks for the input. Yes, I also read someone had a similar problem on the forum. Erratic Temperature Gauge and P0302

Reactions: 1

benmp

Discussion Starter · #20 · 4 mo ago

cougarhound said:
I have to check my coolant because I noticed that the reservoir levels drop every oil change. My guess is that there is a slow leak into the cylinders from a degrading head gasket. I have 240,000 miles on my engine and I will continue drive it and top it off until something blows up. Lol.

Yes, take care!

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