Should I replace head gasket?

[Jbone32]

As i sit here on the side of the road because my alternator rubbed through my lower radiator hose after I adjusted it too low like a knucklehead .. maybe i need a new belt?..wondering also what am i doing with my life and maybe i should recreate 2006 movie produced by Bonzai510 in its entirety while ive got the timing chain and water pump off?..that seems like the logical thing too do but do yall think?

[datzenmike]

I think you may be reinventing the wheel. Unless you can make a better video it's already done.

 

Head gasket??? Don't fix what isn't broken. Replace your timing chain. Enjoy driving your truck.

[Jbone32]

Lol i mean do the head gasket while im in there..nobody can recreate or duplicate the masters moves. Im more concerned that the water pump repacement and timing chan set wont fix the overheating and it could be the head gasket..or even that the gasket is the same age as me and ive been known to blow a gasket from time to time.

[datzenmike]

Only the bearing will fail on a water pump. It doesn't stop pumping water so I would say if you are over heating, changing it won't do much. Which makes me wonder why are you changing the timing chain?????

 

What makes you think the timing chain needs changing?

[Jbone32]

Wint go into time..dizzy is clocked all the way counter clockwise yet timing marks through light are retarded..engine no mater what position i place the dizzy stutters at shut down like its out of time..only overheats over 40mph

[datzenmike]

The drive spindle can be moved to clock the distributor into a better timing position.

 

Run on, or dieseling, is the idle cut solenoid not working, or idle set too high, choke stuck on or part on.

 

None of these things warrant a timing chain or a head gasket. Yet anyway. The timing chain has absolutely no physical connection to the distributor or it's timing.

[thisismatt]

Why stop at one?  Put TWO head gaskets on for double the mileage between changes.

[Jbone32]

Always wondered why not ..more is better right😄

Datzen ive moved the timing to get super close and didn't stutter at shut down..yesterday i drove 40 miles sometimes steep uphill grades and only overheated when i hit the freeway. And after that i have to pull over every mile or so just to get home.its driving me crazy..well..when its driving anyway.. Ambient temp outside about 50 degrees if that..i figure the water pump was shot but what do i know and as far as the timing chain i figured why not as if im doin the pump then might as well..for some reasin i figured it was stretched or skipped due to the timing not going in.

[Jbone32]

Btw choke is not hooked up cause it fires right up cold..new carb 32/36..i used to have to pop the clutch to shut it down like it was dieseling or stuttering trying to shut down but running?..one day idle just ramped up and was fully closed on idle screw and spring from throttle so i turned down idle mixture and now it dies at stop signs without feathering pedal ..i intend to pit it back but i was assuming it was a timing problem..by drive spindle you mean by removing oil pump and moving it a tooth?..right now its at the 11:38 pos at tdc so i dont know whats up ..was considering harmonic balancer was jacked up but doing water pump and timing because PO said he never did either 10 years before parking it for 20 more..lol...i know its a mess

Im exhausted from a full day of work and 2 weeks of this truck. Its why im in replace everything at this point mode..Ive never owned a japanese made vehicle that wants so much blood

Edited March 10, 2021 by Jbone32

[datzenmike]

Don't fix what isn't broken.

 

Find out what is wrong and fix it once.

 

Never 'throw parts' at a problem.

 

 

 

What did you set the timing at? 

 

Causes of over heating usually fall into two categories...

 

Not enough air flow

1/  fan belt loose

2/ clutch fan loose

3/ rad outer fins damaged, missing or plugged with dirt or bugs

4/ fan shroud missing

5/ fan broken or missing a blade

6/ fog lights or bush bar blocking air flow through grill

 

Not enough coolant flow

1/ low coolant

2/ heater hoses joined together to by pass a leaking heater

3/ faulty thermostat

4/ rad inner tubes blocked by hard water scale

5/ soft lower rad hose collapses from pump suction

6/ fan belt loose

 

[Jbone32]

So ive got all these parts stacked up to get started on tomorrow but something is bothering me. This may sound like im paranoid or stupid or both but I changed the oil 2 weeks ago and when i check it with dipstick its so clean its hard to see ..and i mean so clean it looks empty... Is it possible oil pump not working..i would think it would sieze up after a mile or so instead if overheat. 

[datzenmike]

Two months of daily driving might color it a bit, but two weeks isn't enough.

 

If the oil pump wasn't working neither would your engine by now.

 

 

Go back to your other thread about over heating and look at the suggestions.

 

If you have never looked at the thermostat just buy a new 180F and change it. Make sure you get an $8 one not the $1.99 from Cosco or WallMart. There's no sense testing a thermostat that may be 40 years old. The thermostat top has to come off and a new gasket might as well put a new one in.

 

Take radiator cap off. Drain a half gallon out of the cooling system so you can look in and see the tops of the internal tubes. Are they clean and open? or all crusty with hard water scale? If crusty, remove the rad. Keep the hoses on it and undo the engine ends. This will prevent you twisting the radiator pipes and breaking the solder joints. Empty the rad and lay front end down with the cap on. Fill with a bottle of CLR and top up with water. Let fizz for a day or so to dissolve the scale. Rinse and put back on.

 

With engine warmed up, look at the lower rad hose and rev the engine up. Does the hose collapse? Is it really soft and gooey? Replace if either.

 

Check fan belt tension by pushing hard with thumb on the belt half way between the alternator and the fan pulley. At most it should deflect only one belt thickness. Tighten as needed.

 

Are the two heater hoses joined together??? If they are place a wooden dowel or broom handle between then to shut off any flow.

 

Spin the plastic fan. If the clutch is ok it will stop as soon as you let go of the blades. Give it a good spin. If it continues to spin after you let go, the silicon oil inside has leaked out. 

 

 

 

[Jbone32]

Thanks for the reply..i just came out from the driveway working on it " no garage" but.. divorce forces sale .long story ill check out the suggestions over there. I changed the thermostat last week. Bottom hose is solid on accelerate. There was scale in the rad then as well so i put some autozone cleaner in there per instructions and then flushed it..looks clean as a whistle..well at least from the top. Gunna be a long weekend doing timing chain water pump as well as 14" spal  fan and spal 185 relay switch..could have got a new rad for that but while its out im going to clr the shit out of it now that you say that. Anyway it doesn't have a fan clutch just a 3 blade fan cause of broken blade. I know thats not any way to expect it to not overheat but it will idle for hours and stay dead center on the temp gauge..only heats up over 40 or shall we say 4th gear well that was before i just put new points in it 10 mins ago and now its knocking from somewhere?..never knocks at all..trucks driving me insane..dosnt help its cold as balls outside. Btw what do you mean about the broom stick..is this some type of flowery way of a master asking me to sweep the deck 😃

[datzenmike]

Doesn't need a new chain or water pump. These have nothing to do with cooling.

 

Three blade fan should set off alarms when it comes to cooling. It's only running 75% right off the bat. Fix the obvious things that aren't right, save some time an money on things that won't help you cool.

 

If you have an electric fan put it on and you're done.

[Jbone32]

So you think i should just put the parts away for later?..well minus the fan of course..if timing doesn't go in could be bad dizzy or?..sorry tired i get up at 3am and work til 4 every day and fighting with vehicles is taking its toll as well ..lol

[Jbone32]

Somehow due to circumstances this project truck has turned unto the only transportation.." long story" and i just last month got my diesel back from Fabrication turning it into stick shift and its been parked with no time cause im fighting with datsun to run to even get back and forth. Picked up a new uper and lower rad hose today as well..going to put it back together tomorrow and fight with points til i can drive it to the salvage yard and search for matchbox or even tonight get petronix shipped next day cause im in a pinch. ..i just realized what you were talking about with the heater and wood .no..the heater is hooked up but wierd thing is with heater in and blowing even while overheating blows cold..hoses hot to touch..wierd..btw the radiator cap you recommended with the spring came today as well..thanks for that..i really appreciate all your help. 

Edited March 11, 2021 by Jbone32

[banzai510(hainz)]

you have a timing light?

what the timing when this is idleing?  I say 7 to 10 btdc.

 

does this truck get up to 55-65 mph?

 

CRANK at Zero is TDC the tang is 11.28 position.You wrote 11/ 38 I assume this is a error. If it is at 11 38 then your off a tooth and need fixing it . 11/28 then put the distributor on and the rotor should point right on the plug wire with the timing plate pretty much centered with lots of room for adv or retard on the distributor.

 

I dont want to hear about replacving the timing chain to fix the over heating its not going to fix it

 

you never showed a photo of what the dist inside the points look like so ordering a Pertronix migh be a waist of time.

 

you need to slow down  dont be changing shit to change shit. Esp on the ignition yet.

 

Now you fucked with the carb idle and seems you going backwards.

 

cma timed when crank at zero. if looks like this your chain is fine. little of wont hurt either.

oilpumpspindal.bmp

Edited March 11, 2021 by banzai510(hainz)

[mainer311]

Wait a second? This is Hainz? Holy shit!

 

 

[banzai510(hainz)]

crank at zero this what the spinal look like

 

 

maybe your head gasket is bad but lets go thru other stuff first. Maybe that why the guy sold you the truck!!!

 

On the belts maybe you just need a 5mm shorter one. Order for a stock size  be like a 7345 number then the last number is in mm meter so you can figure it out.  Maybe just a need one will be fine as the old one stretched. I have a asorrment of 7345 up to 7360 I believe

 

 

maybe remove the stat and run it w/o it ans see if gets HOT again then you know its pressuzing up in to the radiator

 

oilpumpspindal.bmp

Edited March 11, 2021 by banzai510(hainz)

[datzenmike]

2 hours ago, mainer311 said:

Wait a second? This is Hainz? Holy shit!

 

 

 

 

Yeah, 15-20 years ago when he was slim from jumping out bedroom windows.

[Crashtd420]

17 hours ago, mainer311 said:

Wait a second? This is Hainz? Holy shit!

 

 

I said the same thing first time I realized it...  saw the videos before I ever joined ratsun....

[Jbone32]

On 3/10/2021 at 5:16 PM, datzenmike said:

Two months of daily driving might color it a bit, but two weeks isn't enough.

 

If the oil pump wasn't working neither would your engine by now.

 

 

Go back to your other thread about over heating and look at the suggestions.

 

If you have never looked at the thermostat just buy a new 180F and change it. Make sure you get an $8 one not the $1.99 from Cosco or WallMart. There's no sense testing a thermostat that may be 40 years old. The thermostat top has to come off and a new gasket might as well put a new one in.

 

Take radiator cap off. Drain a half gallon out of the cooling system so you can look in and see the tops of the internal tubes. Are they clean and open? or all crusty with hard water scale? If crusty, remove the rad. Keep the hoses on it and undo the engine ends. This will prevent you twisting the radiator pipes and breaking the solder joints. Empty the rad and lay front end down with the cap on. Fill with a bottle of CLR and top up with water. Let fizz for a day or so to dissolve the scale. Rinse and put back on.

 

With engine warmed up, look at the lower rad hose and rev the engine up. Does the hose collapse? Is it really soft and gooey? Replace if either.

 

Check fan belt tension by pushing hard with thumb on the belt half way between the alternator and the fan pulley. At most it should deflect only one belt thickness. Tighten as needed.

 

Are the two heater hoses joined together??? If they are place a wooden dowel or broom handle between then to shut off any flow.

 

Spin the plastic fan. If the clutch is ok it will stop as soon as you let go of the blades. Give it a good spin. If it continues to spin after you let go, the silicon oil inside has leaked out. 

 

 

 

 

[Jbone32]

So been out there fighting with truck . spoiler...truck is winning ..picjed up a 14 inch low profile puller from spal. Dosnt fit even with mechanical fan off it dosnt fit radiator..funny cause someone said 16 and i went even smaller..lol .. so reversed polarity put it as a pusher...but after i finished up went to start truck and would fire up cause i keft a wire off..which turns out was a good thing because now i can tell the head gasket is blown because instead of burning off i can physically see a leak down the side of the block..oh well 😌 can anyone recomend which head gasket i need for a 74 620 L18 at Rock auto? cause there are four available felpro and others..i say rock auto cause im out of time and need this truck to run and rock auto cones in 2 days here in Cali.

Anyway check out picks i was trying to find the timing mark through hole had it at tdc and this is what it looked like ..wtff ..anyway thanks for all the replies.

 https://ibb.co/m9v4ZXg
https://ibb.co/QChdM52
https://ibb.co/NLW2rfW
https://ibb.co/nnKxGtN
https://ibb.co/rdY80Lq
https://ibb.co/TKwbr7T

Edited March 13, 2021 by Jbone32

[Jbone32]

Well...felt like engine siezed...pulling #2 spark plug upon crank hoses down everything to the passenger side with a gallon of water. 😌

 

Edited March 14, 2021 by Jbone32

[datzenmike]

So over heating has probably warped the head. Oh well'

 

Usually sold as one gasket fits all. The L20B is 86  85mm cylinder bore, same as the L18. Felpro is good enough.

 

Set engine to TDC first.

Might as well change the timing chain.

Never set the head down on the combustion chamber side. Lay down on manifold side.

 

Check the head for warp with a really good straight edge. X pattern and across the center of all cylinders at the narrowest points. If a 0.004" feeler gauge slips under it should be resurfaced.