what is a heat riser? and where is it ? And how to fix ,, car will stalll and not restart when hot

Asked by Jul 17, 2016 at 12:06 AM about the 1975 Dodge Dart

Question type: Maintenance & Repair

car runs great until it gets hot...

3 Answers

59,965

A heat riser is at the bottom of the exhaust manifold,it controls the air flow from the exhaust to keep engine running cool,it is simular to the photo,this is not the one on your Dart but simular.

1 out of 1 people think this is helpful.
Best Answer
59,965

You will have to remove the exhaust manifold to replace,this is the kit for your dart.

1 out of 1 people think this is helpful.
58,815

The heat riser is a "butterfly" type valve just like the choke valve that you see on the top of the carburetor. It's located on the exhaust manifold, as TST has shown. When the engine is cold it should be closed. When it's closed a portion of the hot exhaust gases is directed up around and under the carburetor. This helps fuel atomisation and prevents ice from forming on the throttle plates of the carburetor in cool damp weather. With the engine cold, check and see if you can move the valve freely by hand. If so, the valve is good. A lot of times what happens is the passage in the intake manifold that the exhaust gases flow through gets clogged up with carbon. This can cause the automatic choke to not open up, like it's supposed to when the engine warms up. Some automatic chokes sit in a "well" next to the carburetor. As those hot exhaust gases flow under the "well" it also heats up the choke so it will open like it's supposed to. But if the exhaust passage is clogged the choke won't open and you'll get an overly rich air/fuel mixture. This can cause stalling, not starting when hot, and carbon fouling of the spark plugs. An older mechanic at a good muffler shop should be able to replace or even fix the heat riser valve. But if you can move the valve by hand it's working and you'll have to clean out the passageway in the intake manifold. Lastly, in later years, the name of this heat riser valve was changed to an EFE (Early Fuel Evaporation) Valve. It's the exact same thing except that it'll have a vacuum hose hooked up to it to help it work better. HTH. -Jim

1 out of 1 people think this is helpful.

Your Answer

Add photo

Related Questions

Dart

Looking for a Used Dart in your area?

CarGurus has 15,210 nationwide Dart listings starting at $4,998.

ZIP:

Search Dodge Dart Questions

UK Questions

Are you a UK consumer? CarGurus now has a discussion forum in the UK.

Dodge Dart Experts

#1 enginecreator
enginecreator
Reputation 100
#2 Racer_X
Racer_X
Reputation 80
#2 Rowefast
Rowefast
Reputation 80
View All

Related Models For Sale

Used Dodge Charger
467 Great Deals out of 29,730 listings starting at $2,275
Used Honda Civic
937 Great Deals out of 68,324 listings starting at $1,500
Used Dodge Challenger
351 Great Deals out of 24,969 listings starting at $8,750
Used Ford Mustang
583 Great Deals out of 41,215 listings starting at $1,699
Used Chevrolet Malibu
1,123 Great Deals out of 82,793 listings starting at $1,800
Used Toyota Corolla
1,081 Great Deals out of 64,184 listings starting at $1,595
Used Honda Accord
1,084 Great Deals out of 76,808 listings starting at $1,395
Used Chevrolet Camaro
475 Great Deals out of 39,921 listings starting at $3,499

Used Cars For Sale

2016 Dodge Dart For Sale
33 Great Deals out of 8,137 listings starting at $9,832
2015 Dodge Dart For Sale
99 Great Deals out of 3,475 listings starting at $8,000
2014 Dodge Dart For Sale
57 Great Deals out of 1,095 listings starting at $7,950
2013 Dodge Dart For Sale
116 Great Deals out of 2,432 listings starting at $4,998