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Member Since 20 May 2016
Offline Last Active Nov 15 2017 05:09 AM

#1405499 9-hour Trip North with my 1978 620 pickup; Do the Hustler! Questions...

Posted by wolfmandu on 28 July 2016 - 12:00 PM

Hello my fellow Datsun heads. Wolfmandu here. I have a 1978 620 pickup that I am basically doing all the work on myself. My son and I are about to move north of San Francisco in about a month. We'll be doing a 9-hour drive from L.A. to get there. Our convoy will consist of my son in his old Volvo wagon (with Roscoe the Rotty in the back) and me in my Lil Hustler 620 and hauling my trailer (which is made up of a similar year Datsun 620 truck bed and was built by a great trailer company years ago). I want to be sure I've taken the best pre-cautions I can and have dealt or deal with the obvious things that could go wrong on the longest trip I'll have taken her on since I bought her 6-months ago.

    I have installed a new alternator, fuel-pump, radiator, battery and clutch. My main problem recently has been the cooling system which was solved by installing the new radiator but only after I pulled the new thermostat I put in. My understanding is that this is only a quick-fix and I should figure out why the thermostat isn't opening pretty soon. If peoples' experiences with pulling their 620 thermostats are positive (or negative) please weigh in. I did flush the engine (which has a low 45,000 miles but had been sitting since 1994) about 15 times before I installed the radiator  but I did not buy any flush product and let it sit in the engine for a day or two and then flush it. Should I do this? Could that be the thermo problem?

   As I said before, any and all advice is quite welcome on what I should check before my long trip. I don't want my son and our dog stuck on the side of the road with me, in the crazy recent heat, surrounded by our lives loaded into the Volvo and my Datsun 620 (and trailer). I have a month to try to avoid that outcome.

  I forgot. The most recent fix was the oil pressure plug that screws into the block and has a wire that connects to the gauge. That went bad and dumped a full-engine's oil all over the freeway and the scrap-yard I made it into. Luckily I towed it home and fixed it with no harm coming to the engine.

   Before I go I just want to say how great I think this site is. Everyone helping each-other out and expecting nothing in return is a great thing to witness and experience. My Datsun will be with me the rest of my days and I'm learning how to really fix a vehicle's problems WITH her. I don't have a lot of mechanical experience and all your help so far has been priceless. Thanks again and please weigh in on your advice for getting her ship-shape to set sail for the "Redwoods' of northern California.


       all the best,


#1398678 HELP! Datsun 620 Cooling Problems. NEED ADVICE!!

Posted by wolfmandu on 04 July 2016 - 05:13 PM

Thank you very much for your replies. I should also say that yesterday, after installing the new radiator, I filled it up with water and started the engine. I watched the gauge go from cool to hot in under 4 minutes. Never even got that hot  before, just sitting there, started from cold and at low idle. I am thoroughly perplexed.It's almost as if, now, after installing new fan clutch/water pump, new thermostat and new radiator, it's running hotter than ever before. At least before it didn't get that hot until I took it on the freeway at a higher speed. Any and all advice welcome.

#1398594 HELP! Datsun 620 Cooling Problems. NEED ADVICE!!

Posted by wolfmandu on 04 July 2016 - 08:14 AM

So. I have live in Altadena, CA. I have a 1978 Datsun 620 pickup. 5-spd with the 2.0 engine. Initially the truck was getting very hot (gauge would crawl to the top and I would have to pull it over and let it cool) when I would get on the freeway and go over 45-50 miles an hour. In stop and go traffic it was fine at lower speeds.  I put in a new fan-clutch, thermostat and most recently I pulled the thermostat, flushed the engine out with a hose about 15 times and put in a new 3-row aluminum radiator. The truck had been sitting with the original owner since 1994 so I was hoping the radiator would end up being the problem. I have sunk every extra penny I have in to this truck and am totally in love with it. It will be with me the rest of my days. I don't know if the only problem could be with the head as I think I have trouble-shooted everything else I can think of that might have to do with it getting too hot. I have never done head work on a vehicle and am not even sure what to look for. If there are any Datsun lovers in my area I am hoping that someone might even be willing to take a look at it with me as I'm doing all the work myself. My 620 is a true piece of 70's art and turns head whenever she's out and about. Even got a matching Datsun pickup-bed trailer that I tow behind her and am planning on driving the duo up north with my son but I have to figure out this problem first. Any and all advice will be appreciated. I barely turn the key and she fires over, without hesitation every time. Also, when I first bought her I pulled the dipstick and after having sat for so many years, the oil was a beautiful honey color. I NEED HELP. Thanks in advance to all you Datsun Heads.