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Discussion Starter #1
As a senior design engineer who works on his own cars in my spare time I can always spot the rookie design mistakes on areas of vehicles that they gave junior engineers to work on.

Today's rookie fine was the third 15mm hex bolt on the side mount on my mk1 volt, the top two of course have reasonable access but the third is impossible, I can get a wrench on it but no way to apply enough torque to extract.

Instead of the through hole on that lower third mount, they should have made it slotted with the slot opening pointing downwards, a stud could have been mounted on the block and a serrated nut to hold in place. The load of the engine is against the upper portion of the slot so no need to be captive on the bottom. The two other complete holes with bolts are plenty to prevent any potential upwards movement.

Any tricks to this third bolt? I examined my belt and its in good shape considering 119k on the car now, so I'm good for 6-12 months. I'll need to go back to this at some point and complete the job.

Also the engine mount looks like perhaps it is hydraulic, does anyone know? if it is they usually need replacing at some point due to leakage or deflation.

thanks
 

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Discussion Starter #3
Thanks, I had the engine on a jack so I did raise/lower to try and get it but it didn't work :(

These torque to yield bolts in modern cars are ridiculous, who came up with such a terrible idea??? I'm guessing bolt companies to sell more bolts, next will be biodegradable bolts that must all be replaced every 3 years, maybe I should patent that??
 

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I've seen way worse on VW. Their solution is to remove and replace the ENGINE. Instead of giving 1mm more space to clear an oil line? I worked around that with pass through ratchets and gear wrenches and some wiggling and gentle prying.

I'd bet you could access it by removing the wheel and wheel well liner or using a gear wrench. Maybe a small pancake ratchet.



 

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Discussion Starter #6
Thanks everyone, I bought a whole bunch of new stretch bolts and am going to attempt this again this weekend. I will plan on a full day.
I also plan on adding some blue threadlock to the bolts as an extra safeguard from loosening.
 

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I use Loctite on a regular basis but not on high torque situations.
 

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Discussion Starter #8
Got it done, it was a pain of a job. To get that last lower bolt out required various raising and lowering of the engine and feeding it through some pipes against the bodywork. Really tricky.

Feeding the new belt on wasn't too hard, the old belt was 7 years old and 120k miles and looked in great shape. The belt seems very high quality so I'm not swapping this for another 10 years lol

I did use some blue threadlock as an extra precaution against loosening.
 

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I was believing that the Volt had an electric water/coolant pump, not a mechanical pump with a belt to the crankshaft as in common ICEVs. I have seen the engine bay of the Ford Fusion Hybrid and it has no belts at all on the 2 liter gas engine. All the accessories are electric, including an electric engine coolant pump.
 

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I was believing that the Volt had an electric water/coolant pump, not a mechanical pump with a belt to the crankshaft as in common ICEVs. I have seen the engine bay of the Ford Fusion Hybrid and it has no belts at all on the 2 liter gas engine. All the accessories are electric, including an electric engine coolant pump.
The Volt has an electric coolant pump, and a conventional water pump on the engine. Here's a quote from WOT's excellent article:

Whenever the 1.4 liter range extender ICE is ON, coolant through the engine is managed by a conventional belt-driven water pump. A belt driven pump was selected to ensure positive cooling flow whenever ICE is ON, that is automatically varied proportionately with engine speed. The thermostat regulates the normal engine operating temperatures in a conventional fashion, but can be heated electrically to speed opening and regulate flow. Thus the thermostat creates an appropriate flow restriction for the engine cooling loop that promotes a positive coolant flow and helps to limit air cavitation. When the engine is first started and the thermostat remains closed, a hot water bypass line permits heated coolant flow to the electric pump and heater core. Once the thermostat opens, flow will be permitted through the radiator which will maximize cooling yet still allow flow through the heater core loop for passenger compartment heating.

I recommend reading all of WOT's article at this link:

https://gm-volt.com/2010/12/09/the-chevrolet-volt-coolingheating-systems-explained/
 

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Did you replace the belt and pump or just the belt?
 

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I was believing that the Volt had an electric water/coolant pump, not a mechanical pump with a belt to the crankshaft as in common ICEVs. I have seen the engine bay of the Ford Fusion Hybrid and it has no belts at all on the 2 liter gas engine. All the accessories are electric, including an electric engine coolant pump.
You really need to get your hands on a Volt.
 

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The hard coolant lines for I believe the battery pack need to have there brackets lessened this gives you room to remove the bottom bolt from engine mount bracket....

yes stretch to yield bolts suck but guess they have a place sometime my Supra (mk4) head was held down with them I had it for 20 years made over 500rwhp for me st of it and I had reused those bolts just like service manual said I could only had head off by I dropped a valve when doing valve stem seal replacement I did wish I had gotten better arp bolts but they held for my long life with the car and I drove it incredibly hard for a very long time never messed with bottom end of motor. Amazing car and engine
 

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I was believing that the Volt had an electric water/coolant pump, not a mechanical pump with a belt to the crankshaft as in common ICEVs. I have seen the engine bay of the Ford Fusion Hybrid and it has no belts at all on the 2 liter gas engine. All the accessories are electric, including an electric engine coolant pump.
I think that's true for Gen 2.
 
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