sadoldgit Posted August 13, 2014 Share Posted August 13, 2014 Just fitted a Disco 200TDi to replace the cracking 19j that JST sold me seven years and 100k ago. Before fitting it I noticed that the wastegate was stiff to operate so freed it off by lots of judicious working and WD40 and hoping that a good dose of heat would sort it out once the engine got some use. What are the symptoms/consequences of a seized closed wastegate and what is the standard boost pressure? Cheers, Paul Quote Link to comment Share on other sites More sharing options...
Scotts90 Posted August 14, 2014 Share Posted August 14, 2014 Symptoms: going from turbo'd petrol experience, if the wastegate doesn't open or sticks shut then you'll find you have a noticeable increase in boost as the rpm increases...standard boost is 0.85bar I think. Now this is all fair and well and you may have a grin on your face right up until it all goes Pete Tong. Which leads nicely on to... Consequences: potential engine damage or complete failure. Increasing boost is fine until the fuelling can no longer keep up, this can melt pistons and knacker blocks. If you're lucky, the increased pressure could blow off a boost pipe before getting to the engine damaging stage. Manufacturers design the engines for longevity and reliability so any increase is going to affect the lifespan, 200s are now 20+ yrs old and it's testament to the design they have lasted so long. Petrol engines running mega boost will have ARP studs to hold it all together, wire ringed blocks/steel head gaskets, increased flow/larger injectors , bigger intercoolers, uprated actuators and the ecu tweaked to suit. It's all to easy to up boost settings and enjoy the power but without considering other components (clutch/gearbox etc) is a ticking time bomb. Quote Link to comment Share on other sites More sharing options...
CwazyWabbit Posted August 14, 2014 Share Posted August 14, 2014 Symptoms: going from turbo'd petrol experience,........... Increasing boost is fine until the fuelling can no longer keep up, this can melt pistons and knacker blocks....... In the world of diesel if the fuelling can't keep up then there is not so much of an issue, diesel engines control speed purely based on how much fuel is put in (they have no throttle bodies to control air flow). Melting pistons is more likely to occur with excess fuel. That said excessive boost can result in turbos failing and throwing bits of metal into the engine, if you also increased the fuel you would then get all the joyus symptoms of which Scotts90 has described. Quote Link to comment Share on other sites More sharing options...
ian_s Posted August 14, 2014 Share Posted August 14, 2014 i tested the wastegate on my tdi by attaching a bike tire pump to it and pumping carefully. it took a bit of faffing to get the hoses to seal well enough but it worked in the end Quote Link to comment Share on other sites More sharing options...
sadoldgit Posted August 14, 2014 Author Share Posted August 14, 2014 Cheers chaps, not had much chance to test the 'Old Girl' since I fitted the new engine. A week of working outside in the pishing rain and lying underneath it in puddles seems to have done my back in. Not even had a chance to get it good and hot to give a good blast but I'll keep my eye on the boost pressure when I do. Thanks, Paul Quote Link to comment Share on other sites More sharing options...
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