EGR and turbos - cracked heads anybody

[Vultch]

caught this off another site by accident

What follows applies to Renault 1.5DCI engines, but may explain why the diesel turbochargers fail: The EGR valve should open to allow carbon dioxide (which acts as a cooling gas) into the combustion chambers when the engine is under load (>30% boost). This allows the combustion chamber temperature to drop and thus the temperature of the exhaust gases. If it sticks in the closed position the exhaust gas temperature will rise causing a) the turbo bearings to fail and b) engine oil into the induction system. This can cause the engine to run on its crankcase oil until it is either stalled or goes bang. Problems with EGR valves are often the cause of rough running when the valve is stuck in the open position as well. In several cases turbos have blown but the EGR valve has not been replaced. Inevitably the new turbo unit will not last long.

In fact... would dis connecting our EGR on our Surf's be the reason for so many cracked heads....

[BUSHWHACKER]

It's the poor design of the waterways in the heads that causes them to crack. They have been cracking with EGR valves connected too.

[MattF]

In fact... would dis connecting our EGR on our Surf's be the reason for so many cracked heads....

No.

[gwh200]

After owning one for a short while, I can say absolutely the reason that this Renault blows up is because renaults are piles of shit

[Vultch]

After owning one for a short while, I can say absolutely the reason that this Renault blows up is because renaults are piles of shit

At last a reasoned explanation.....

[fonecrusher1]

After owning one for a short while, I can say absolutely the reason that this Renault blows up is because renaults are piles of shit

Very true. My dad had one years ago, what a heap.

[guysturg1]

After owning one for a short while, I can say absolutely the reason that this Renault blows up is because renaults are piles of shit

couldn't agree more, need a plastic clip for an electric window (common failure) as one on a mates clio broke, renault dealer price £130, they only do the complete assy!!

[BUSHWHACKER]

We had a 2001 Clio 1.5 dci, lovely car with no problems. Maybe it's because I look after my vehicles??

[Growler]

We had a 2001 Clio 1.5 dci, lovely car with no problems. Maybe it's because I look after my vehicles??

I still have one as my every day work car and can honestly say I can't fault it Did over 28k in it in 12 months and only issue was a rear wheel bearing failure.
Regular servicing goes a long way IMHO

[BUSHWHACKER]

I still have one as my every day work car and can honestly say I can't fault it Did over 28k in it in 12 months and only issue was a rear wheel bearing failure.
Regular servicing goes a long way IMHO

Oh yeah, I remember now, I had to replace a rumbly rear wheel bearing too.
Actually I replaced both sides, simple enough job though.

[NiftyNev]

The EGR does not operate under load. Not on a Surf anyway. The EGR is there to lower emissions and not to protect the turbo or anything else.

Nev