454 No heat

RV and bus conversion info since 1996.

Share Your Feedback

PRINT PAGE

RV Classifieds

		1985 Monaco Crown Royale - $56,000
		2005 Bigfoot Ind 25B175CB - $23,500
		2000 Winnebago Adventurer - $64,500
		1982 MCI MC-9 - $55,000
		1972 Prevost LeMirage - $49,900
		VIEW ALL
		Search RV Classifieds
		Classifieds Policies
		Benefits for Dealers
		Sell Your RV
		Dealer Signup

Useful Links

RV Community

		Discussion Groups
		RV Articles
		RV FAQs
		RV Classified Ads
		Virtual RV Park
		Shop at our Store
		RV Lifestyle Books
		Rate Your RV
		AllThingsRV.com
		MyRVGuide.com
		RVMechanic.com
		Advertise With Us

BECOME A MEMBER

RV Resources

		e RV Loans
		Sculptures for your RV
		Visit Rio Rancho, NM for Winter
		RV Dealers
		RV Manufacturers
		RV Rentals
		RV Glossary
		RV Types
		RV Ratings

454 No heat

Home > Discussion Forum > Mechanic's Corner - Engines

email Todd

reply to message

post new message

search forums

hidden layer

ATTENTION: All Postings that advertise items for sale will be deleted from the Discussion Forum. You may post sale items for free in the Classifieds section. Sign up now.

All Messages in Thread	Author	Date
454 No heat	Todd	2-1-07
1995 454 that only provides heat when idling. I get 148 degrees out of the heat vent when idling then drops to 70 degrees when driven a few miles or with engine rev’d for a few minutes The problem started about 5 years ago. Have put on 20,000 miles since the problem started. The engine has never overheated and the temp gage runs consistently around 210. The engine runs like a champ – it just doesn’t heat! Here’s what I’ve done over the past 6 years and have run out of ideas: 1.The coolant supply line comes from the back of the block - goes to the bottom connection of heater core. 2.The coolant return line is on the top connection of the heater core and connected to the top of the radiator. 3.Checked/replaced thermostat and radiator cap 4.Checked/replaced heater control valve to make sure it's working 5.Checked for correct vacuum pressure to the control valve 6.Checked the outside of heater core box to make sure it's sealed completely to fire wall. 7.Checked the blend air door in the heater control box to see that it's moving and not disconnected inside 8.Checked the nipple coming out of the engine for blockage 9.Replaced supply and return hoses 10.Checked for a possible air lock in the heater core by bleeding the return line 11.Installed clear tube in supply line – small bubbles at idle – all foam at higher RPMs 12.Coolant block tester – indicated low level of CO2 in coolant 13.Magnafluxed heads – no cracks, some warping - planned heads and replaced 14. Replaced - water pump and heater core 15.Still have small bubbles at idle and turns to foam at higher RPMs 16. Replaced hoses 17. Rechecked vacume lines 18. Replaced heater core What in the world could this be? * small hole in the block? * blockage in one of the waterjackets? * still a crack in one of the heads? I'm running out of ideas - help
Re: 454 No heat	richard	2-2-07
I have a 84 pace and 98 Bounder both heater circuits come off top front of water pump to heater core and output from heater core back to intake- i dont have connection on back of engine My service manual shows the exact way to run coolant lines and never shut off flow thru heater core. rich in Va.
Re: 454 No heat	mike e	2-2-07
My Itasca same as Richards no connections from back of block. 1986 Mike
Re: 454 No heat	Todd	2-18-07
It's a 1996 block casing number 10237297...454.......96-up...4-bolt, Vortec 7400", "L-29" Gen.VI The heater supply hose comes out the back. I also checked my 1992 chevy pickup - it has a 305. the heater supply comes out the back of the block as well. I'm afraid I might mess something if I reroute the coolent flow without finding out the correct flow for this engine. Does anyone know where to get a diagram for the coolant flow?