... lots of air, but it's not hot. And occasionally when the car accelerates or goes around a corner, I can hear a "sloshing" water sound behind the dash. The obvious would seem to be that I didn't get coolant into the heater core, but I did all the steps (that I know of). After I filled up the block and radiator (using the hose and expansion tank), I turned on the heat full blast ... then topped off the coolant, then started, then ran the heat full blast again. Driving around the engine temp stays just around 80, no weird fluctuations, whether the heat is turned on or off. Did my aux pump just decide to stop participating, or is there something I'm missing as far as getting coolant sucked into the core? I can't imagine there's not enough coolant in the block to allow it to happen ... I put almost 9 quarts in, and as I said, the engine temps are great. No funny smells coming out of the vents, no loss of coolant (so far). Heat worked super before I did the flush.
Should I try pouring coolant directly into the heater core hose?

__________________
1987 300D, arctic white/palomino--314,000 miles
1978 240D 4-speed, Euro Delivery, light ivory/bamboo--370,000 miles
2005 Jeep Liberty CRD Limited, light khaki/slate--140,000 miles
2018 Chevy Cruze diesel, 6-speed manual, satin steel metallic/kalahari--19,000 miles
1982 Peugeot 505 diesel, 4-speed manual, blue/blue, 130,000 miles
1995 S320, black/parchment--34,000 miles (Dad's car)

You need to burp that baby. Park it with the nose uphill, remove the radiator cap, run the engine with the heater wide open until the air burps out.

__________________
1977 300d 70k--sold 08
1985 300TD 185k+
1984 307d 126k--sold 8/03
1985 409d 65k--sold 06
1984 300SD 315k--daughter's car
1979 300SD 122k--sold 2/11
1999 Fuso FG Expedition Camper
1993 GMC Sierra 6.5 TD 4x4
1982 Bluebird Wanderlodge CAT 3208--Sold 2/13

Probably shouldn't need to be said, but here goes: don't remove the radiator cap when it's hot.

It needs "burping".
Heater temp on max.
I have found best results with motor cold to get the air out of the heater coil.
Is your heater aux pump working?

__________________
Grumpy Old Diesel Owners Club group

I no longer question authority, I annoy authority. More effect, less effort....

1967 230-6 auto parts car. rust bucket.
1980 300D now parts car 800k miles
1984 300D 500k miles
1987 250td 160k miles English import
2001 jeep turbo diesel 130k miles
1998 jeep tdi ~ followed me home. Needs a turbo.
1968 Ford F750 truck. 6-354 diesel conversion.
Other toys ~J.D.,Cat & GM ~ mainly earth moving

The way I've been lately, everything needs to be said.

I should clarify, this is the 87 300D. From what I've read it burps itself through the line on top of the block, but I did fill on either side of the t-stat using the upper radiator hose, then filled the expansion tank. I'll try starting it with the expansion tank cap off tomorrow when it's cold and see if anything burps out.

__________________
1987 300D, arctic white/palomino--314,000 miles
1978 240D 4-speed, Euro Delivery, light ivory/bamboo--370,000 miles
2005 Jeep Liberty CRD Limited, light khaki/slate--140,000 miles
2018 Chevy Cruze diesel, 6-speed manual, satin steel metallic/kalahari--19,000 miles
1982 Peugeot 505 diesel, 4-speed manual, blue/blue, 130,000 miles
1995 S320, black/parchment--34,000 miles (Dad's car)

It was ... now I'm not so sure. The sloshing leads me to believe there is not the right amount of coolant going into the heater core. But maybe an air bubble is preventing the pump from working. Will try running it for a while with cap off (cold).

__________________
1987 300D, arctic white/palomino--314,000 miles
1978 240D 4-speed, Euro Delivery, light ivory/bamboo--370,000 miles
2005 Jeep Liberty CRD Limited, light khaki/slate--140,000 miles
2018 Chevy Cruze diesel, 6-speed manual, satin steel metallic/kalahari--19,000 miles
1982 Peugeot 505 diesel, 4-speed manual, blue/blue, 130,000 miles
1995 S320, black/parchment--34,000 miles (Dad's car)

There must be good flow through the radiator, so that part is good.

There is apparently air in the pipe that leads through the aux. pump, up and over to the heater core.

Turn on the key but don't start the engine, with the heater switched on, heat turned to max., and fan on low. You should be able to stand at the driver's fender and hear the aux. pump humming (under the washer-fluid tank). If not, it's seized.

With the car running, feel the hose running up from the aux pump, it should be warm/hot. If not, is the hose coming out of the LR corner of the head and up under the intake hot (that one leads from the head to the aux. pump)?

I recently put a new dry engine in my '87, filled both directions from the upper radiator hose with the expansion tank cap off, secured the hose, topped off, started the engine and all was fine. Yours should do the same.

__________________

Gone to the dark side

- Jeff

Well ... I can definitely hear the pump whirring with the air on/engine off. And, once the car is warmed up, the hose running to the heater core is hot. Today the air blowing out was definitely warmer than it was the other day, but not full-out hot like it used to be. And I can still hear a little "slushing" sound coming from the dash, albeit only occasionally (two days ago I heard it every time I accelerated). So obviously the pump it getting coolant, but I can't understand why the air isn't blowing at full temp. Other than that, everything is fantastic ... the car stays at 80 or right above. Maybe there's just a little bubble in the heater core gradually working it's way out. As said, two days ago the air was blowing cold; today it's slightly hot but not rip-snorting hot.

__________________
1987 300D, arctic white/palomino--314,000 miles
1978 240D 4-speed, Euro Delivery, light ivory/bamboo--370,000 miles
2005 Jeep Liberty CRD Limited, light khaki/slate--140,000 miles
2018 Chevy Cruze diesel, 6-speed manual, satin steel metallic/kalahari--19,000 miles
1982 Peugeot 505 diesel, 4-speed manual, blue/blue, 130,000 miles
1995 S320, black/parchment--34,000 miles (Dad's car)

Hopefully it will continue to work its way out with high RPM/flow, heater operation on high temp (max. flow), and some acceleration to move bubbles forward.

__________________

Gone to the dark side

- Jeff

I drove up and down some hills.

This is kind of a silly question, but when it does work its way out, it will just go to the top of the reservoir tank, and the level will drop, right? I've just been carrying around some coolant and keeping a close eye on the level.
aaa, hills might be a good idea ... all my test driving has been extremely flat!

__________________
1987 300D, arctic white/palomino--314,000 miles
1978 240D 4-speed, Euro Delivery, light ivory/bamboo--370,000 miles
2005 Jeep Liberty CRD Limited, light khaki/slate--140,000 miles
2018 Chevy Cruze diesel, 6-speed manual, satin steel metallic/kalahari--19,000 miles
1982 Peugeot 505 diesel, 4-speed manual, blue/blue, 130,000 miles
1995 S320, black/parchment--34,000 miles (Dad's car)

Yes, the air will make its way to the expansion tank.

__________________

Gone to the dark side

- Jeff