I've got a '96 F-350 that drains the HPOP reservoir after cranking, and won't start when the temp is below about 15*.

I've searched and can't find anything with quite my symptoms. When I go out in the morning the reservoir is full. I'll crank for a while, it'll blow white smoke, but won't catch. Then I check the reservoir and it's really low, and if I fill it up then she'll start. Once she's started she runs like a champ, doesn't stall like I've heard a worn LPOP will do. Any ideas? This is my first post, so forgive me for the length.

 

Mine does something simular, only it starts fine and then dies about 15 seconds later with the reservoir empty. Has done it since I bought it in 2002.
I've learned that if the oil is old and overdue this problem is guanteed to arrive when it gets below about 20*. This winter I tried something new and went to a full synthetic 5-40 oil and so far the cold starts have been great. I believe mine has a LPOP issue that doesn't allow it to fill the HPOP reservoir if the oil is too thick.

How old is your oil? You make it sound like you have to crank it for a bit to start? Maybe that's all you problem is, cranking speed too slow to keep reservoir full? Should fire within 5 seconds of cranking

 

if you fix your glow plugs your problem will likely resolve itself.

richard

 

What brand oil filter? if it does not have an anti drainback valve i could see that.or a lpop that doesn't pick up oil fast enough.i have seen plenty worn out. also the timing cover could wear at the pump.aaaanndd there is the valve in the filter head aanndd the check valve on drivers. upper front in block.
all possibilites.
welcome aboard as well!!

 

Oil has 2,000 miles, it's RotellaT 15w-40. I've heard that changing to synthetic after a couple hundred thousand miles it will leak, how'd it work for you?

Yes I do have to crank for a while. The starter is brand new, and batteries are fairly new. But they have had a rough time lately.

I just replaced the GPR, haven't had a chance to check the GPs yet. Is the ohm test the best way to check them?

I run Motorcraft oil filters. What's this check valve in the upper front block you speak of? That's the only one I haven't heard of...

 

You can try changing to a lower viscosity oil for winter months like 5w-40 or 10w-30. Full synthetic WILL find a way to clean out your engine and ruin your old seals. You're probably just better off running a thinner dino oil.

There's a check valve in the HPOP itself. Not your issue, since you stated that the reservoir is full before you try to start it.

 

Yea, Use an ohm meter to check each glow plug. As far as the switch to synthetic causing leaks.... that is a wives tail.

The only nuget of truth might be that the detergents in synthetics last longer and clean out the gunk on the back of some seals that might have been plugging existing leaks.

synthetics do not cause leaks, at the most they can show existing leaks.

Richard

EDT: I run Rotella T6 Synthetic and according to the oil analysis I am fine at 7700 miles OCI. If it is fine again I might extend it to 10k miles. Keep in mind I do not tow much at all and it takes over a year to go that 7.7k miles.

 

I didn't mean to say that synthetics would cause leaks... I meant that they clean out too much. In my experience (it's happened to me a few times on different engines now) anything that's been sealed up by old dino oil will get cleaned out and the old seal will start leaking.

So not directly caused by the synthetic, but caused by what the synthetic oil does when it cleans out your oil passages and seals.

 

Richard, I think you were right, finally found my volt meter and tested the GPs. 4 came up bad, so in the process of replacing them. The PO did them about 4 years ago, but he used Autolites. Hopefully this fixes all the starting issues.

 

Have you already been told not to replace those with more Autolites? The only ones that I've ever heard recommended are the Motorcraft/Beru plugs. Autolites are known for swelling up at the tip, so watch that when you pull them. If you could afford it, I'd go ahead and replace all 8 with Motorcraft. You can order them from Riffraff's website. Or you can check the parts stores - ask them specifically for the motorcraft plugs. I know AutoZone carries some in my area. If you don't replace them all now, you'll have this same problem down the road...sooner probably than later.

 

+1 DO NOT USE AUTOLITES!!! I have had to pull the heads of multiple motors I have serviced due to swelling and the snapping of those ******* plugs. Only go Motorcraft of BERU. Period. Its around 90$ for 8 new BERU plugs through RIFFRAFF, and believe it or not Oreillys actually had Motorcraft GPs as well, kinda surprised, I noticed they now carry motorcraft batteries too.

Its one thing to do plugs, but pulling heads is much more expensive for a customer.

 

Yeah, I was surprised when I heard that AutoZone had the Motorcraft Plugs...not sure if all do though. I would hate to have to pull the heads because of something as silly as a bad glow plug. I guess you'd have to if the tip broke off...not sure if there would be anything else you could do.

 

That means you have 8 bad glow plugs....

 

Thanks guys, yeah I replaced them all with Motorcrafts from O'Reilly's. Luckily all the plugs came out fine, no swollen tips. And, best of all she fired right up. Although, it hasn't been very cold the last couple days.

 

I have had my truck in cold temps a few times (0-10*F) and it's a California truck, so that's definitely not normal at all. I run Rotella T 15w-40, did the Stancor GPR mod, LPOP and HPOP are in good shape, and my EBPV operates properly. I have found that even when the motor sits and gets down into the 30's, you're going to experience at least a little harder start than normal. If it's a REALLY cold day (in the 20's for us California folk), I will cycle the GP's a couple times before I even crank, get them suckers and the combustion chamber good and warmed up. Then my truck cranks up fine.

If you still have a hard start problem in the cold, check and see if you have a block heater, and if you don't, install one. It sounds to me like you have having oil circulating trouble, mixed with faulty GP's. Now that you got your GP's fixed, try the block heater and you should be golden showers. The block heater will help heat the motor oil so it will cycle into your HPOP easier.

Note: if you blow your GPR (like I did once in Big Bear), and you don't have an extension cord to power your block heater because you live in California and don't ever need the darned thing, you can still get your truck to start--even without glow plugs.
::WARNING:: This is a field expedient method ONLY to get a froze up diesel to start. Don't catch your truck on fire, because that's not my fault.

Start a SMALL fire in a trashcan lid or a bucket. Once the fire is going, plop that sucker under your oil pan. DO NOT LET THE FLAMES LICK UP ON YOUR MOTOR, YOU CAN START A FIRE IF THERE IS OIL, PS FLUID, BRAKE FLUID, OR FUEL PRESENT FROM LEAKS. You just want the heat to warm your pan up nicely (It took me about 30 minutes burning pine cones, needles, and twigs at about 5*F). Then, once your pan is warmed up a little, your oil will cycle much easier. Crank the heck out of it and the compression will heat up the combustion chamber eventually and it will fire up. It only took me about 30 seconds of cranking to build up enough cylinder heat to fire. High compression diesels (23-25:1) don't use GP's, ours at 17-19:1 need some help with heat.

Hey, use common sense, this is only a last resort when you're in a pickle. If you burn down your truck, I hold no responsibility. This is merely a suggestion when you're out of other options, like suggestions on how to mickey mouse an ORV to get you off the trail. Now go forth and start really cold trucks