Car is slower after being stuck in traffic?

[Phal]

Car often feels like its lost some power after Ive been stuck in traffic.

It often feels quite perky first thing in the morning or first thing when I leave work but then after its been running it feels like its lost some power and often feels like its lost more if Ive been stuck in traffic crawling along for 25 minutes :\


MAF is fine since its only about 6 months old and the turbo is only a year old.



The engine does seem to sound different though when its lost power - almost like the turbo isnt working as hard as it should since I cant hear as much whine from the turbo :/ but then its all back to normal by the next time I drive it until I get stuck in traffic again :\


Its an Audi A4 - 2.5 V6 TDI - 99

 

[rG-tom]

it's called heat soak

 

[L0rdMike]

it's called heat soak

He's right.

 

[Phal]

Yeah but if I have the car running constantly without getting stuck in traffic, it feels fine. The engine is still up to temperature at the end of my 30 mile journey but feels crap when Ive been sitting in traffic in first gear but feels ok when I havent :\

 

[rG-tom]

is it an auto? if not, are you slipping the clutch? and by running constantly do you mean moving, or sat still? if it's moving the air movement cools it down

 

[Jez]

Yeah but if I have the car running constantly without getting stuck in traffic, it feels fine. The engine is still up to temperature at the end of my 30 mile journey but feels crap when Ive been sitting in traffic in first gear but feels ok when I havent :\

This tallies perfectly with what has been said

 

[Matt-Page]

Yeah but if I have the car running constantly without getting stuck in traffic, it feels fine. The engine is still up to temperature at the end of my 30 mile journey but feels crap when Ive been sitting in traffic in first gear but feels ok when I havent :\

Put the blowers on hot to release some of the hot air. Check things like the air filter, etc.

What car is it? What engine?

 

[TripleT]

Because when you're stuck in traffic you hardly move and the engine sucks up the warm air from the engine bay (heat sock).

When you're moving, even just at 30mph, the air temp is noticibly cooler.

 

[TripleT]

Put the blowers on hot to release some of the hot air. Check things like the air filter, etc.

What car is it? What engine?

I'd guess mk2 v6 mondeo going by his sig.

 

[L0rdMike]

I'd guess mk2 v6 mondeo going by his sig.

Tom didnt start the thread.

 

[TripleT]

Tom didnt start the thread.

Oh hell ignore me, only got a small window open

Apologies.

 

[atpbx]

I'd guess mk2 v6 mondeo going by his sig.

Or a Its an Audi A4 - 2.5 V6 TDI - 99

Like it says in his post

 

[Phal]

Its an Audi A4 2.5 V6 TDI like it says in my first post!


Anyway, yes I know that the engine is cooled a lot more when my car is moving with the constant flow of air.

The trouble is, even after I get out of the traffic, the car continues to feel sluggish all the way home. It has about 10 miles of road to cool down before I get home but still doesnt seem to get back to normal :/

 

[rG-tom]

I'd guess mk2 v6 mondeo going by his sig.

n00b

 

[jimblowscash]

Its an Audi A4 2.5 V6 TDI like it says in my first post!


Anyway, yes I know that the engine is cooled a lot more when my car is moving with the constant flow of air.

The trouble is, even after I get out of the traffic, the car continues to feel sluggish all the way home. It has about 10 miles of road to cool down before I get home but still doesnt seem to get back to normal :/

it would take a good run of 40mph+ to reduce the heat under the bonnet, hense the fact the car still feels sluggish, its worse with bigger engined cars as well as theres a lot more crammed under the bonnett hense it needs more air flow.

its not just the engine, its the engine bay as well, basicaly anything that will radiate heat in the bay will heat up the air that goes through the intake, a cheeky way of helping this allong would be to get a 9.99 halfrauds flexy hose and feed one end through the wheelarch or grill and the other directly on to the filter or in the airbox. hotter air is less dense than cold air therefore a greater volume of hot air is needed to produce the same performance / rate of combustion than cold air, and if your running a std air box etc you will notice a big difference in performance.

 

[Dogbreath]

Put the blowers on hot to release some of the hot air.

The interior fan does not suck hot air from the engine bay to keep you warm, the heat comes from the engine cooling system via a heater matrix (small radiator) under the dashboard.

 

[Overlag]

The interior fan does not suck hot air from the engine bay to keep you warm, the heat comes from the engine cooling system via a heater matrix (small radiator) under the dashboard.

yup... might reduce engine temps very slightly, but not inlet air

 

[DuncyBoy]

Anyone got a link to more info on Heat Soak? Always ready to expand my knowledge.

Quick Question: my Dad, when stuck in traffic on a hot day, winds the windows down and angles the vents out the window on hot to help cool the engine. Is this pretty much pointless then?

 

[Dogbreath]

It can help cool the engine if the radiator and it's cooling fan are not adequate (unlikely in a modern car unless something is fautly).

 

[Overlag]

It can help cool the engine if the radiator and it's cooling fan are not adequate (unlikely in a modern car unless something is fautly).

my mates old fiesta needed this trick to keep it cool, also another mates mini needed this before he found a working radiator fan lol