6.9 Block Heater Cracking Issue

[OleRed]

There are different kinds of block heaters besides the ones that go in a freeze plug in the block. I have a 90 with a 7.3 IDI in it. when the block heaters went bad, I put one in the heater hose( got it from NAPA). it has a pump inside of it and it heats and pumps hot coolant through the whole system. This means that the heater and defroster work as soon as you start the pickup.

The reason I did this is not because of the block cracking issue as I have heard of that. The reason I did it is that it only took about an half hour to install instead of the several hours to half tear the pickup apart to replace the stock ones.

Just an FYI

Steve, That's a good point about the hose heater, and I might end up doing that. As you said, the plug doesn't leak now, so it might be worth bypassing the risk altogether.

Ford F384, thank you for the detailed answer. I think that may be the culprit to the hard starts. I've cleaned the cable connections pretty thoroughly and the batteries are only a year old, but I have no idea about the age of the starter. Temps here get to maybe 10-20 at worst overnight, so the motor should fire right up without even having to use a block heater, which would eliminate that problem for me. I'll check on the starter (for all I know it's original), and if I end up going with a new one or something along that route, I'll update the thread.

Thank y'all very much for the details responses and help, I appreciate it a ton

[Ford F834]

Steve, That's a good point about the hose heater, and I might end up doing that. As you said, the plug doesn't leak now, so it might be worth bypassing the risk altogether.

Ford F384, thank you for the detailed answer. I think that may be the culprit to the hard starts. I've cleaned the cable connections pretty thoroughly and the batteries are only a year old, but I have no idea about the age of the starter. Temps here get to maybe 10-20 at worst overnight, so the motor should fire right up without even having to use a block heater, which would eliminate that problem for me. I'll check on the starter (for all I know it's original), and if I end up going with a new one or something along that route, I'll update the thread.

Thank y'all very much for the details responses and help, I appreciate it a ton

I like the block heater even if your low’s are still within GP starting. It just ‘feels’ like you are being nicer to the engine, and gives you peace of mind that it’s not going to give you a hard time especially if it’s your only transportation. If you have the later block, I wouldn’t hesitate to use the stock heater.

[ArdWrknTrk]

Steve, That's a good point about the hose heater, and I might end up doing that. As you said, the plug doesn't leak now, so it might be worth bypassing the risk altogether.

Ford F384, thank you for the detailed answer. I think that may be the culprit to the hard starts. I've cleaned the cable connections pretty thoroughly and the batteries are only a year old, but I have no idea about the age of the starter. Temps here get to maybe 10-20 at worst overnight, so the motor should fire right up without even having to use a block heater, which would eliminate that problem for me. I'll check on the starter (for all I know it's original), and if I end up going with a new one or something along that route, I'll update the thread.

Thank y'all very much for the details responses and help, I appreciate it a ton

If you do end up wanting a starter here's one for $85 delivered (no core)

https://rover.ebay.com/rover/0/0/0?mpre=https%3A%2F%2Fwww.ebay.com%2Fulk%2Fitm%2F174487849329

Again, these may be rebuilds, but I can assure you anything with UHR is completely refurbished.

Their business depended on Ford trucks and vans 30 years ago and downtime meant lost profits.

They also have NOS Motorcraft starter cable assembly's for these solenoid style starters.

To anyone else.... there's a whole lot of 460, 6.9 & 7.3 parts there.

But you're going to be searching through tens of thousands of parts.

[OleRed]

If you do end up wanting a starter here's one for $85 delivered (no core)

https://rover.ebay.com/rover/0/0/0?mpre=https%3A%2F%2Fwww.ebay.com%2Fulk%2Fitm%2F174487849329

Again, these may be rebuilds, but I can assure you anything with UHR is completely refurbished.

Their business depended on Ford trucks and vans 30 years ago and downtime meant lost profits.

They also have NOS Motorcraft starter cable assembly's for these solenoid style starters.

To anyone else.... there's a whole lot of 460, 6.9 & 7.3 parts there.

But you're going to be searching through tens of thousands of parts.

Jim, thanks for the link Looks like a great option

[6.9-250]

Several good points have been brought up here already. Prior to purchasing my truck i did come across that cracking issue from the oem block heater. I cant recall for sure the years but i think the 85 was one of them, something to do with a weak point in the casting (i think).

Definitely have to start with the starting system. Clean terminals on both battery's. The oem alternator is 65 amps (i believe). I doubt this is enough to keep the batteries topped up over time. I regularly disconnect the batteries (just the grounds) and charge each battery separately using a 1 amp noco smart charger. Slow charging is best for these batteries.

These engines are famous for air intrusion also. The return system is common for leaking. Return kits are available and not very expensive or hard to install. I have a schrader valve by my fuel filter. If yours does, depress it prior to start. You should get a small shot of diesel. If not it will take some cranking to purge the air out and bring up fuel pressure (could be a sign of the fuel system leaking down). It says you replaced the injection pump, did you time it after? Incorrect timing will give you hard starting as well.

Test the glow plugs using an ohm meter (or DVOM). Testing with a test light will not give you a good result of the condition of the plug, just shows working or not working. Test if the system is actually supplying power to the glow plugs when the key is turned on (check both banks). Many recommend Motorcraft plugs and that is what i used as well. Other brands may swell when burnt and you dont want to deal with trying to remove those from the head. My controller stuck on and burnt my motorcraft plugs, zero swelling. I converted my system to manual after that and recommend others do it. Cold start, you should get about 10 seconds of glow plugs.

I currently have 3 engine heaters on mine and about to add a 4th.

The factory block heater - I use this only when I need the truck quicker due to the cracking possibility.

Lower rad hose heater - doesn't work really great and is likely due to not being mounted low enough in the system.

Oil pan heater - silicone electric pad mounted to the bottom of the oil pan. Installed because I keep 15W40 in it year round. Works great to warm up the oil. Once the oil warms it will start to radiate up and warm the engine as well. I bought a low wattage one though - i think 125 watts, so that would take awhile.

When all 3 are plugged in - warms the entire engine nicely.

I am hoping to get away from the rad hose heater and block heater. I have purchased a circulating block heater. Most are 1500 watts and that is a full line load for most outlets. Chances of tripping a breaker are much higher. I found one that was 850 watts and plan to install in the near future (not looking forward to seeing if I can get the block drain plug out - after 35 years of being in there). There is no pump in these type so it needs to mounted very low - thermosiphon technology. So i will use this and the oil pan heater.

I start it in low temps such as -30C (-22F)

All of my fuel is treated with Alliant Power - ultraguard. It improves the cold filter plug point for winter temperatures.

Some lab tests show better results then Stanadyne (likely a very good product as well).

 

[OleRed]

Several good points have been brought up here already. Prior to purchasing my truck i did come across that cracking issue from the oem block heater. I cant recall for sure the years but i think the 85 was one of them, something to do with a weak point in the casting (i think).

Definitely have to start with the starting system. Clean terminals on both battery's. The oem alternator is 65 amps (i believe). I doubt this is enough to keep the batteries topped up over time. I regularly disconnect the batteries (just the grounds) and charge each battery separately using a 1 amp noco smart charger. Slow charging is best for these batteries.

These engines are famous for air intrusion also. The return system is common for leaking. Return kits are available and not very expensive or hard to install. I have a schrader valve by my fuel filter. If yours does, depress it prior to start. You should get a small shot of diesel. If not it will take some cranking to purge the air out and bring up fuel pressure (could be a sign of the fuel system leaking down). It says you replaced the injection pump, did you time it after? Incorrect timing will give you hard starting as well.

Test the glow plugs using an ohm meter (or DVOM). Testing with a test light will not give you a good result of the condition of the plug, just shows working or not working. Test if the system is actually supplying power to the glow plugs when the key is turned on (check both banks). Many recommend Motorcraft plugs and that is what i used as well. Other brands may swell when burnt and you dont want to deal with trying to remove those from the head. My controller stuck on and burnt my motorcraft plugs, zero swelling. I converted my system to manual after that and recommend others do it. Cold start, you should get about 10 seconds of glow plugs.

I currently have 3 engine heaters on mine and about to add a 4th.

The factory block heater - I use this only when I need the truck quicker due to the cracking possibility.

Lower rad hose heater - doesn't work really great and is likely due to not being mounted low enough in the system.

Oil pan heater - silicone electric pad mounted to the bottom of the oil pan. Installed because I keep 15W40 in it year round. Works great to warm up the oil. Once the oil warms it will start to radiate up and warm the engine as well. I bought a low wattage one though - i think 125 watts, so that would take awhile.

When all 3 are plugged in - warms the entire engine nicely.

I am hoping to get away from the rad hose heater and block heater. I have purchased a circulating block heater. Most are 1500 watts and that is a full line load for most outlets. Chances of tripping a breaker are much higher. I found one that was 850 watts and plan to install in the near future (not looking forward to seeing if I can get the block drain plug out - after 35 years of being in there). There is no pump in these type so it needs to mounted very low - thermosiphon technology. So i will use this and the oil pan heater.

I start it in low temps such as -30C (-22F)

All of my fuel is treated with Alliant Power - ultraguard. It improves the cold filter plug point for winter temperatures.

Some lab tests show better results then Stanadyne (likely a very good product as well).

6.9-250, thank you for the detailed answer. Battery's are new and the terminals are good/tight, though I might start to slow charge them as it gets colder.

Glow plugs are good as well, no air leaks, and the IP was timed. I'm thinking of installing a manual bypass at some point.

Still have to figure out if my block is a pre-block heater fix casting until I use the heater.

However, just as an update to the thread and to anyone who might have the same problem I had with hard starts:

I took out the old starter and put a new gear reduction one in over the weekend (a Nippondenso - part # 16658N - https://www.qualitypowerauto.com/catalog.php?item=35). That top bolt was a PITA to get out, but feeling around with my left hand and using a 10 inch extension for my socket wrench in the right finally got it out. This new starter is a BEAST. I can hear and feel it turning the motor over much faster than the old starter (which I believe was original), and the truck starts right up now, even after sitting overnight.

Of course, I still have to see if it starts as easy when it gets really cold and the truck's outside (I've had it in the garage). I'll probably end up plugging in the heater just to make it easier on the motor and/or getting a circulating block heater, as many have recommended, which is probably the best option in terms of longevity. If I end up going that route, I'll update this thread for the sake of whoever might find it helpful.

Thank you all again for the great advice. The hard-start/cold-start problem seems to be solved for now.