Cooling System Woes

['70dime]

So this past week I've had some unusual cooling system issues. First let me tell you about my system. Brand new aluminum radiator (I know skib denounces the use of these but I was in a pinch and the radiator shop refuse to fix mine again), New 185 deg thermostat, and stock shroud and fan. Stock L20, weber downdraft, dogleg, maybe a mild cam. Also I'm trusting a stewert warner gauge that might be 30 years old. I've noticed lately that my car smokes quite a bit until it gets to temp, it doesn't smell like coolant though. So today by the time I get on the interstate I'm up to temp, not smoking so much, temp 190. I'm cruisin at about 3k rpm and I notice the temp is climbing, so I start to slow down to pull over and the temp comes back down. so the rest of the ride to work I keep it at 2.5k rpm and it stays at 190, droped to fourth and at 3k+ the temp starts to climb, back in 5th at 2.5k the temp comes back down.

 

Once I get off the interstate I notice the heater is cold and the temp is climbing. Then I have heat and temp starts going back down.

 

Its been doing this sorta thing for a min, and my first thought was blown head gasket, but we ran a block tester last night and the test came out alright (may have done it wrong, I'll try again this weekend). Also we did a pressure test on the cooling system and after tighening a barely loose hose clamp it would hold 15 psi. I'm also losing coolant though, but I dont know if it running hot and dumping out of the over flow is causing the loss of coolant, or its losing coolant into the engine, then running hot because of lack of coolant, then dumping out of the over flow. There are coolant stains in the engine bay but I can't replicate when it runs hot in the drive way.

 

What do you guys think? What should I check? Maybe a air pocket in the system?

 

This is my only ride and I depend on it to get me to work, I really appreciate any help.

 

Pierce Jones

[banzai510(hainz)]

heater cold means no water in most cases.

 

ck the lower hose nad make sure its not collasping when you rev up the motor.

 

if white smoke make sure the intake/lower bolts that are flush with the exhaust manifold bolts are tight if you run a water line to the intake manifold.

Sometimes they may be loose and suck water in. Or the intake gasket is getting bad/cracked.

 

if you get a pressure test look at the lower intake and se if water is comming out there.

 

on the heater make sure the valve is open under the driver side. soemtime the cable doesnt opne it all the way to let hot water in. I usually just leave the heat on and use the vent so I dont wear out the valve

 

 

if spark plugs 2 and 3 are nice and clean I would think its the intake manifold gasket.

['70dime]

Okay, I'll check the hose on my lunch break, the pressure test will have to wait till I get home. Also thanks for you video on L series rebuilding, it helped me do my first head gasket.

[banzai510(hainz)]

you could alwasy reck the head gasket tightness if in dought but if spark plugs 2 and 3 aree clean that means is most like sucking in water from the water passage.

I assume this is a stock L16 with the water passage/hot water line to the intake to heat the manifold.

 

later L20s(reread your post as you have a L20) might not have this so a photo would help to see if a hot water line is installed or mayb ethe head has the water passage holes but your not running a water line. Im guessing

['70dime]

Its a L16 intake, I have a intake gasket coming so this weekend I should be able to replace that depending on what the plgs look like. I'll see if I can get a photo on lunch break to show my setup.

[zed]

I'm no expert, but I would also check the thermostat - I had a new one on my Landcruiser go bad in less than 100miles. Is your water pump good? Also have you felt with your fingers all around the ends of the hoses and clamps - I find leaks easier that way

['70dime]

The water pump is fairly new, I think I'm gonna pick up another thermostat tonight and give it a shot also while I'm there. I got new hoses on the way also, but I'll double check the ones on there when I take a lunch break.

[metalmonkey47]

Sounds like empty rad or no coolant circulation?? If you need s hand with it today, let me know man. I'm off and may be able to shoot over there.

['70dime]

Sounds like empty rad or no coolant circulation?? If you need s hand with it today, let me know man. I'm off and may be able to shoot over there.

 

Yes, that is true to an extent, because coolant is dissappearing. I'm gonna check some things on lunch.

[racerx]

may want to check your rad reservoir..happened to me once where the reservoir had a small leak and did not notice it till later when I placed a cardboard underneath to see where it was leaking. 

[racerx]

you can slo try boiling your thermostat and place a temp. gauge inside the pot and see when it opens. 

['70dime]

may want to check your rad reservoir..happened to me once where the reservoir had a small leak and did not notice it till later when I placed a cardboard underneath to see where it was leaking. 

 

Yea, my brother mentioned this just now, I don't have a resevoir. I've never had an issue before, we're gonna pick one up tonight and hook it up to see if it helps. Also I'm gonna pick up a new termostat because it seems like it might be stuck open because higher engine speed make it run hotter the coolant might be flowing through the radiator faster than the radiator can do its job.

 

Thanks everyone for your help, I'll do some work tonight when I get home and let y'all know what I find out.

[ssnapz]

test the cap too, if it dont hold pressure it will let the water out the over flow

['70dime]

test the cap too, if it dont hold pressure it will let the water out the over flow

 

Will do! I hadn't thought of that because its new, but I'm willing to try anything at this point.

[Lee R]

Hit it with the timing gun....if it's not timed right it can cause it to heat up as well.

[racerx]

you mentioned..is it white smoke...Does it smoke a lot at intersection, hopefully your headgasket did not go out.  Check your dipstick to see if the oil is like chocolate shake - if so then headgasket. Also do a compression check and see what is normal range for the car.  Maybe 150 or so.

['70dime]

It smokes when its cold, not so much when it warms up, I'll check the oil before I leave work.

[datzenmike]

All cars have white 'smoke' at this time of year.

 

SW gauge? Get an infra red temp gun and shoot the thermostat housing and see if you can trust SW.

 

If you have your old thermostat put back in and see.... Even if you buy a new one it won't hurt to have it for trouble shooting in the future..

 

 

I had a 5 year old '64 Dodge slant six and the steam and smoke that came out the back would cover two lanes. Only happened when I gave it the gas. I pulled over lifted the hood and there was coolant everywhere but no leak!!!! Finally in frustration I revved the shit out of it.... and there was a pin hole in the heater hose that shot over and was sucked in the air filter snorkel. Only blew out under pressure but not at idle. It happens.

 

So rev it up in the driveway and see if there are any leaks. Also check the lower rad hose like Hainz says. The return side of the rad is the suction side and if the hose has gone soft it Will collapse.

 

 

Leave the rad cap loose so you can check level next time it runs up into the HOT range. If it hits the HOT range and is full of water then it can't be because it's low.

[racerx]

yeh true to smoking a lot during winter time but if there is a lot of white smoke, specially at intersection and dipstick looks like chocolate shake. then it's for sure the headgasket is gone.

['70dime]

okay, the cap is holding 15 lbs as it should, the lower hose isn't collapsing, the thermostat is opening at the correct temp. I couldn't find a overflow at the store so I'll have to find one from somewhere else. I did back the timing off a few degrees. It did the same thing this morning although not as bad, cruisin to work, temp chillin at 190. Then nothing else changed (speed, traffic, nothing) and the temp creep past 190 and kept creepin, so I pulled over sat for a min. When I started it back up to check the temp it started coming back down, settled at 190. I took off and had no issues the rest of the way.

 

I'm gonna swap the old radiator back in tonight and see what that does, it leaks a lil bit but I never overheated with it.

[banzai510(hainz)]

what the timming light say? Og you dont have a timming light?

 

what temp state you running? 160 180 195?

 

I always drill a 1/8 hole in them anyways myself.

 

make sure to run 50/50 antifreeze mix it keeps the front cover from cacvitatiing

['70dime]

The timing light wasn't working so I went by the marks on the distributer plate, my brother will bring home a timing light tonight. 180 thermostat, I didn't drill a hole, anti-freeze is 50/50 mix.

[banzai510(hainz)]

plate dont mean nothing. ove rthe years and dizzy swaps it can vary alot.

Even my timming changes and the dizzy dont move. lots of varibles soemetimes.

 

I drill a hole to help get rid of air faster, just depends if you heater line has the lower bypass hose from the lower stat housing to the heater line.

 

yes ck the radiator. if there was a noticable change.

 

water pumps only go bad when the bearing wears out. Most of the time the stat is near clowsed so it dooesnt really move alot of water. But seen a water pump where the impellers where almost gone from running only water andf rotted/cavitated it out.

['70dime]

I'll drill a hole tonight, and I don't have any heater bypass lines.

 

Thanks for your help!

[racerx]

if you have the money it's good to invest in a digital timing light.  Or you can get one that has a dial on the back of the timing light (analog). Both can tell you actual timing of the car. I found my dial one on Craigslist for like $10/bucks.