305 V6 timing chain/Water Pump Question - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Alaska_Ryan · 10-19-2009, 01:22 AM

So I was riding along in my 69 GMC, which has a 305 V6 engine. I just got it running again this past June after an engine fire. So, the entire truck shudders and it sounded as though someone threw a chain at the truck. My first though was the drive train broke free and I was dragging it along. I pull over and I am dumping coolant all over the road. When I opened the hood, coolant was dripping from everywhere. When I limp it along, the engine and entire truck just shakes.

So does anyone have any ideas?
Did my timing chain break or jump, thus the shuddering? Seems to be a bit much for a bad water pump....

Lakewood90712 · 10-19-2009, 02:18 AM

Sounds like one of the blades on the fan broke-off. Or a broken motor mount.

hayhauler71 · 10-19-2009, 08:34 PM

Are you sure that when the coolant let loose [possible bearing in the water pump] that the coolant got the ignition system wet.

finadic · 10-20-2009, 12:19 AM

is there really a 305 v-6 ? If so new to me. I only new of the v-8. My water pump berring went out it made a hell of a grumble but did'nt loose to much coolent like you did.

*2tons of fun* · 10-20-2009, 12:36 AM

yes, there is even a 351, in fact there is a 702 v12 that is based dirrectly off of the 351 v6, it uses the same pistons, heads, intakes.

if it shudderd like than you make have wadded up the valve train and what you may have felt was the pistons and valves bouncing off each other.

you may have also cooked the motor from coolant loss [for whatever reason] and felt it seizing up and grinding to a halt.

**Bob B.** · 10-20-2009, 01:18 AM

Can you tell where the water is coming from? Does it shake when the engine is running or only when you drive the truck?

Alaska_Ryan · 10-22-2009, 02:28 AM

Looks as though Lakewood90712 hit it right on the head. It gets dark early in Interior Alaska this time of year so I didn't notice the damage but...

One of the fan blades sheared right off, causing the motor (and entire truck) to shake. Of course, the now airborne fan blade cracked the fan cowling and punched right thru the top portion of the radiator. Which explains why my radiator is still half filled with coolant. It only sprays out the top hole when It gets under pressure. So a new fan, fan cowling and radiator and I should be back in business.

The only problem is the parts for a 305 V6 are a pain in the a$$ to find. Sure can't get them at NAPA

WyoRoadDog · 10-22-2009, 06:09 AM

I'm surprised you can't get them at your NAPA. They're the only ones that don't look at me like I have to heads when I come in for parts! Helps though that one of my NAPA guys had a '66 with a 305 in it.
Watch ebay for the fan shroud, they come up fairly often. Or someone else here might know of another option that would cross over. Or maybe this is your inspiration to do an electric fan swap!

10-19-2009, 01:22 AM	#1
Alaska_Ryan Registered User Join Date: Jul 2008 Location: Delta Junction, Alaska Posts: 7	305 V6 timing chain/Water Pump Question So I was riding along in my 69 GMC, which has a 305 V6 engine. I just got it running again this past June after an engine fire. So, the entire truck shudders and it sounded as though someone threw a chain at the truck. My first though was the drive train broke free and I was dragging it along. I pull over and I am dumping coolant all over the road. When I opened the hood, coolant was dripping from everywhere. When I limp it along, the engine and entire truck just shakes. So does anyone have any ideas? Did my timing chain break or jump, thus the shuddering? Seems to be a bit much for a bad water pump....

10-19-2009, 02:18 AM	#2
Lakewood90712 Registered User Join Date: Jan 2006 Location: so. cal Posts: 111	Re: 305 V6 timing chain/Water Pump Question Sounds like one of the blades on the fan broke-off. Or a broken motor mount. __________________ 1987 GMC heavy half Shortwide-GONE 1971 LWB 350/350-GONE 1972 Buick Skylark (80K orig. miles,one family owned) 2002 Currie Phat Flyer (Pit Vehicle) STOLEN .............................................. Last edited by Lakewood90712; 10-19-2009 at 02:32 AM.

10-19-2009, 08:34 PM	#3
hayhauler71 Registered User Join Date: Aug 2009 Location: St. Paul MN. Posts: 1,996	Re: 305 V6 timing chain/Water Pump Question Are you sure that when the coolant let loose [possible bearing in the water pump] that the coolant got the ignition system wet.

10-20-2009, 12:19 AM	#4
finadic Registered User Join Date: Jan 2009 Location: Dallas Georgia Posts: 24	Re: 305 V6 timing chain/Water Pump Question is there really a 305 v-6 ? If so new to me. I only new of the v-8. My water pump berring went out it made a hell of a grumble but did'nt loose to much coolent like you did.

10-20-2009, 12:36 AM	#5
2tons of fun Account Suspended Join Date: Jan 2009 Location: galt ca, Posts: 749	Re: 305 V6 timing chain/Water Pump Question yes, there is even a 351, in fact there is a 702 v12 that is based dirrectly off of the 351 v6, it uses the same pistons, heads, intakes. if it shudderd like than you make have wadded up the valve train and what you may have felt was the pistons and valves bouncing off each other. you may have also cooked the motor from coolant loss [for whatever reason] and felt it seizing up and grinding to a halt.

10-20-2009, 01:18 AM	#6
Bob B. Senior Member Join Date: Aug 2005 Location: Los Angeles Posts: 1,326	Re: 305 V6 timing chain/Water Pump Question Can you tell where the water is coming from? Does it shake when the engine is running or only when you drive the truck? __________________ 1967 GMC CM-2500 Camper Cruiser, 351E V-6, NP 435 4 speed, Dana 60, and factory A/C. 2012 GMC K-3500 WT regular cab, 6.0L Vortec, 6L90.

10-22-2009, 02:28 AM	#7
Alaska_Ryan Registered User Join Date: Jul 2008 Location: Delta Junction, Alaska Posts: 7	Re: 305 V6 timing chain/Water Pump Question Looks as though Lakewood90712 hit it right on the head. It gets dark early in Interior Alaska this time of year so I didn't notice the damage but... One of the fan blades sheared right off, causing the motor (and entire truck) to shake. Of course, the now airborne fan blade cracked the fan cowling and punched right thru the top portion of the radiator. Which explains why my radiator is still half filled with coolant. It only sprays out the top hole when It gets under pressure. So a new fan, fan cowling and radiator and I should be back in business. The only problem is the parts for a 305 V6 are a pain in the a$$ to find. Sure can't get them at NAPA

10-22-2009, 06:09 AM	#8
WyoRoadDog Page intentionally left blank. Join Date: Jul 2006 Location: Laramie, WY Posts: 299	Re: 305 V6 timing chain/Water Pump Question I'm surprised you can't get them at your NAPA. They're the only ones that don't look at me like I have to heads when I come in for parts! Helps though that one of my NAPA guys had a '66 with a 305 in it. Watch ebay for the fan shroud, they come up fairly often. Or someone else here might know of another option that would cross over. Or maybe this is your inspiration to do an electric fan swap! __________________ There is a theory which states that if ever anyone discovers exactly what the Universe is for and why it is here, it will instantly disappear and be replaced by something even more bizarre and inexplicable.There is another theory which states that this has already happened. - Douglas Adams '67 GMC 4x4, 305 V6! Or all the parts for anyway... '17 Subaru Outback. '18 Toyota Tacoma TRD Off Road. '99 Ducati 900SS.



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