Could a fender bender cause a head gasket failure?

96FZJ80

96FZJ80

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I'm out of town - son is driving the LC so I'm missing some details....

Nov 5 son rear ended a pickup truck. It was a 35mph zone, he did step on the brakes prior to impact but can't guess how fast he was going. Said his body hurt for a couple days afterwards. So glad that is the only issue.

Son said there was a puddle of what looks like coolant in the back side of what is now a mangled OEM front bumper. I had some premixed red coolant in the truck - filled up radiator and reservoir.

Drove it to a shop the next day to have it checked out (do not want to involve my insurance company for my vehicle if I can avoid it). They put it up and checked for any leaks, pressurized the cooling system, and let it run for an hour or so and found nothing wrong. That was Nov 8 - the Monday after the accident.

Truck ran fine - son driving noticed no difference from before the accident.

Nov 14 reported that the reservoir almost empty. No puddles, nothing wet, no drips on the ground. Had him refill the reservoir and pull the dipstick to see what the oil looked like. Oil looked like oil - have no idea if checking the oil on the dipstick would indicate anything or not but what the hell. He thinks I know what I'm talking about.

Nov 17 CEL lit up. Had him get the code from the Ultragauge. P0306 - misfire cylinder 6. Cleared the code with the Ultragauge to see if it would come back. Maybe the accident jarred some wire loose somewhere. This time the coolant level in the radiator is low and the reservoir is above the full line.

Nov 24 - got the early morning text "there's a lot of white smoke coming out of the exhaust". Started doing it on his way to work which is about 5 minutes from the house. Had him drive it back home and park it where it's been ever since.

So... after all that, as the title says, is it possible that the accident somehow rattled/jolted things around enough to open up a gap in the head gasket? Assuming, of course, that's what the problem is. The truck has never had the head gasket changed (it's at 225k) so maybe things are just old and worn enough that a solid bump made it happen? Even if it is just sooner than it would have happened without the accident?
 
M

Michael Hanson

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With cars anything can happen, is it the gasket or a cracked head ? Mike
 
96FZJ80

96FZJ80

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Going into a shop next Tuesday (first opening) to do a compression test and go from there. Could be a cracked head I guess. There's an Ultragauge installed with engine temp on the "home page" and watched religiously. I'm confident it has not overheated.
 
BILT4ME

BILT4ME

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Going into a shop next Tuesday (first opening) to do a compression test and go from there. Could be a cracked head I guess. There's an Ultragauge installed with engine temp on the "home page" and watched religiously. I'm confident it has not overheated.
Unlikely that an impact would cause a head gasket failure.

What it most likely caused is a separation of the upper or lower tank from the fins due to flexing of the core support. This can cause the radiator to push out fluid to the overflow, but not have the cooling suction to draw it back in.

The "smoke" he's seeing is likely condensation in the exhaust based on weather changes and now looking for issues that have been there all along.

Pressure test the cooling system.
Do a compression test for peace of mind.
Check the PS system for leaks and cut hoses.
Check the PHH and rear heater lines for leaks, as an impact can stretch a hard hose and cause it to crack or leak when warm.
 
96FZJ80

96FZJ80

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I'll take a bad radiator any day of the week but the system was pressure tested right after the accident and no leaks found. Taking it to a different shop this time (one that knows 80s), with any luck they'll find that it just needs a new radiator.

I thought about condensation being the reason for the heavy exhaust but not being there to see it for myself I don't want to risk driving it possibly doing more harm than good. When it goes in next week it'll be on a flatbed.
 

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